Combined machining method for miniature angular contact ball bearing ring channel

Abstract

The invention discloses a combined machining method for a miniature angular contact ball bearing ring channel, and relates to a machining method for a bearing ring channel. The problems that an existing miniature angular contact ball bearing ring with a groove belt straight slope structure is low in grinding efficiency and precision are solved. According to the method, a grinding wheel integrated forming and cut-in grinding method is adopted, the surface roughness of the channel after fine grinding meets the design requirement, meanwhile, the fine grinding amount is 0.005-0.01 mm, straight slope fine grinding is not carried out, the diameter of the channel after fine grinding is reduced, the straight slope is higher than the channel, and the locking point requirement is met. According to secondary circulation of coarse grinding circulation and final grinding circulation, stabilization treatment is conducted between the coarse grinding circulation and the final grinding circulation at the same time, and precision and stability are gradually improved. The diamond roller is adopted for trimming the groove belt, the straight slope shape consistency is good, the CBN grinding wheel is high in durability, the CBN oilstone is adopted for finely grinding the groove, the formability is good, all the qualities meet the requirements, the machining efficiency is remarkably improved, the productivity is increased, and the product quality percent of pass reaches 92% or above.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of machining method of bearing ring raceway. BACKGROUND

[0002] The ring of the structure of micro angular contact ball bearing (P4 level) is the raceway of straight slope structure, and the structure is as shown in Figure 1 The curvature of the raceway of the micro angular contact ball bearing is only R1.38, and the size tolerance is +0.02; the raceway axial width is close to 1mm; the straight slope width is 0.6~1mm; the raceway and straight slope lock point height is required to be 5 μm; the raceway diameter is less than 13 mm. The original processing method of the product with the structure is that the raceway curvature radius is manually modified arc with single-point diamond pen, then the straight slope is modified, and then grinding is carried out; the grinding wheel is MA or A / WA abrasive grinding wheel. The grinding wheel diameter is less than 13 mm, and the effective width is maximum 2 mm. In the grinding process, the grinding wheel is easily worn, and cannot meet the continuous processing requirements. The grinding efficiency is low, the precision is not easy to guarantee, and the waste rate is high. SUMMARY

[0003] The present application proposes a kind of compound processing method of raceway of micro angular contact ball bearing ring to solve the problems of low grinding efficiency and low precision of the micro angular contact ball bearing ring with raceway and straight slope structure.

[0004] The compound processing method of raceway of micro angular contact ball bearing ring is carried out according to the following steps:

[0005] Step one, raceway and straight slope grinding

[0006] First, the raceway and straight slope of the micro angular contact ball bearing ring are machined, then the diamond roller is used to modify the grinding wheel, then the modified grinding wheel is used to carry out raceway and straight slope coarse grinding, stable treatment, raceway and straight slope fine grinding, raceway and straight slope final grinding in turn; the diamond roller has the same shape of raceway and straight slope as the bearing, the size of the raceway on the diamond roller is the same as the size of the designed raceway on the bearing ring, and the height of the straight slope on the diamond roller is lower than the lowest point of the raceway by 0.005~0.01mm;

[0007] After the raceway and straight slope coarse grinding, the remaining machining allowance of the raceway and straight slope is 0.04~0.08mm; after the raceway and straight slope fine grinding, the remaining machining allowance of the raceway and straight slope is 0.02~0.06mm; after the raceway and straight slope final grinding, the remaining machining allowance of the raceway is 0.005~0.01mm, and the straight slope has no machining allowance.

[0008] Step two, raceway lapping

[0009] The oil stone is used to carry out channel fine grinding, the fine grinding amount is 0.005-0.01 mm, and the channel surface roughness reaches 0.05 μm after fine grinding.

[0010] The principles and benefits of the present application are:

[0011] In the present application, the channel structure of the angular contact ball bearing ring is a straight slope locking point structure, and the straight slope is higher than the channel. Therefore, the grinding wheel is integrally formed and cut into the grinding method. After fine grinding, the channel surface roughness reaches the design requirement, and the fine grinding amount is 0.005-0.01 mm. The straight slope is higher than the channel after fine grinding, which reduces the diameter of the channel and meets the locking point requirement. The present application has two cycles of coarse grinding and final grinding cycles, and stable treatment is carried out in the middle of the coarse grinding and final grinding cycles, which gradually improves the precision and stability. The diamond roller used in the present application has good straight slope shape consistency, the CBN grinding wheel has high durability, the CBN oil stone is used to fine grind the channel, the formability is good, and all the quality meets the requirement, which significantly improves the processing efficiency, increases the production capacity, and the product quality qualified rate reaches more than 92%. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 It is a structure schematic diagram of the diamond roller in embodiment 1.

[0013] Figure 2 It is a structure schematic diagram of the angular contact ball bearing ring with channel and straight slope obtained in embodiment 1.

[0014] It is a structure schematic diagram of the diamond roller used. DETAILED DESCRIPTION

[0015] The technical scheme of the present application is not limited to the following specific embodiments, and also includes any reasonable combination between the specific embodiments.

[0016] Specific embodiment one: the composite machining method of the micro angular contact ball bearing ring channel in the present embodiment is carried out according to the following steps:

[0017] Step one, grinding of channel and straight slope

[0018] First, the channel and the straight slope are machined on the micro angular contact ball bearing ring. Then, the diamond roller is used to trim the grinding wheel. Then, the trimmed grinding wheel is used to carry out coarse grinding, stable treatment, fine grinding, and final grinding of the channel and the straight slope in sequence. The diamond roller has the same shape of channel and straight slope as the bearing. The size of the channel on the diamond roller is the same as the size of the designed channel on the bearing ring. The height of the straight slope on the diamond roller is 0.005-0.01 mm lower than the lowest point of the channel.

[0019] The machining allowance of the groove and the straight slope after the rough grinding is 0.04-0.08 mm; the machining allowance of the groove and the straight slope after the fine grinding is 0.02-0.06 mm; the machining allowance of the groove after the final grinding is 0.005-0.01 mm, and the straight slope has no machining allowance.

[0020] Step two, groove lapping

[0021] The groove is lapped by using an oil stone, and the lapping amount is 0.005-0.01 mm, and the surface roughness of the groove reaches 0.05 μm after lapping.

[0022] The embodiment has the following beneficial effects:

[0023] In the embodiment, the groove structure of the angular contact ball bearing ring is the groove and straight slope locking point structure, and the straight slope is higher than the groove. Therefore, the grinding wheel is integrally formed and cut into the grinding method. After lapping, the surface roughness of the groove reaches the design requirement, and the lapping amount is 0.005-0.01 mm. The straight slope is not lapped, so that the diameter of the groove is reduced after lapping, the straight slope is higher than the groove, and the locking point requirement is met. The two cycles of the rough grinding and the final grinding cycle in the embodiment are stable, and the precision and stability are gradually improved. The diamond roller used in the embodiment has good shape consistency, the CBN grinding wheel has high durability, the groove is lapped by using the CBN oil stone, the formability is good, all the qualities meet the requirements, the processing efficiency is significantly improved, the production capacity is increased, and the product quality qualified rate reaches more than 92%.

[0024] Specific implementation method two: the difference between the embodiment and the specific implementation method one is that the type of the grinding wheel in step one is CBN270K grinding wheel; the CBN270K grinding wheel uses cubic boron nitride abrasive, the abrasive particle size is 270 mesh, and the hardness of the abrasive is medium hard (K level); the CBN270K grinding wheel has high durability and good formability.

[0025] Specific implementation method three: the difference between the embodiment and the specific implementation method one or two is that the grinding of the groove and the straight slope in step one is performed on a 3MZ143 numerical control bearing outer ring groove grinder.

[0026] Specific implementation method four: the difference between the embodiment and any one of the specific implementation methods one to three is that the temperature of the stable treatment in step one is 135°C, and the time is 3-4 hours.

[0027] Specific implementation method five: the difference between the embodiment and any one of the specific implementation methods one to four is that the groove lapping in step two is performed on an SF11B lapping machine.

[0028] Sixth embodiment: the difference between this embodiment and the first to fifth embodiments is that: the channel finishing in step two adopts CBN5000ZXA or CBN8000 ZXAI oilstone.

[0029] Seventh embodiment: the difference between this embodiment and the first to sixth embodiments is that: after the channel and straight slope rough grinding in step one, the machining allowance reserved by the channel and straight slope is 0.04-0.08mm; after the channel and straight slope fine grinding, the machining allowance reserved by the channel and straight slope is 0.02mm; after the channel and straight slope final grinding, the machining allowance reserved by the channel is 0.005-0.01mm, and the machining allowance reserved by the straight slope is 0.

[0030] Eighth embodiment: the difference between this embodiment and the first to seventh embodiments is that: after the channel and straight slope rough grinding in step one, the machining allowance reserved by the channel and straight slope is 0.08mm; after the channel and straight slope fine grinding, the machining allowance reserved by the channel and straight slope is 0.02-0.06mm; after the channel and straight slope final grinding, the machining allowance reserved by the channel is 0.005-0.01mm, and the machining allowance reserved by the straight slope is 0.

[0031] Ninth embodiment: the difference between this embodiment and the first to eighth embodiments is that: after the channel and straight slope rough grinding in step one, the machining allowance reserved by the channel and straight slope is 0.04-0.08mm; after the channel and straight slope fine grinding, the machining allowance reserved by the channel and straight slope is 0.04mm; after the channel and straight slope final grinding, the machining allowance reserved by the channel is 0.005-0.01mm, and the machining allowance reserved by the straight slope is 0.

[0032] Tenth embodiment: the difference between this embodiment and the first to ninth embodiments is that: after the channel and straight slope rough grinding in step one, the machining allowance reserved by the channel and straight slope is 0.04-0.08mm; after the channel and straight slope fine grinding, the machining allowance reserved by the channel and straight slope is 0.02-0.06mm; after the channel and straight slope final grinding, the machining allowance reserved by the channel is 0.01mm, and the machining allowance reserved by the straight slope is 0.

[0033] Example 1

[0034] The machining process flow of the ring of the micro angular contact ball bearing (P4 grade) structure in this example is: bar stock→ fine turning plane→ turning outer circle→ drilling→ fine turning cutting surface→ turning channel and straight slope→ inverting inner and outer angles→ heat treatment→ fine grinding plane→ rough grinding outer circle→ final grinding outer circle→ grinding outer ring inner circle→ channel and straight slope rough grinding→ low temperature supplementary tempering (stabilization treatment)→ channel and straight slope fine grinding→ channel and straight slope final grinding→ channel finishing→ grinding outer diameter→ typing→ submission

[0035] The grinding process for the grooves and slopes is as follows: First, the grooves and slopes are machined on the miniature angular contact ball bearing rings. Then, a diamond roller is used to dress the grinding wheel. Following this, the dressed grinding wheel is used to perform rough grinding, stabilization treatment, fine grinding, and final grinding of the grooves and slopes. The diamond roller has grooves and slopes of the same shape as the bearing. The dimensions of the grooves on the diamond roller are the same as the dimensions of the grooves designed on the bearing rings. The height of the slope on the diamond roller is 0.01 mm lower than the lowest point of the groove. After rough grinding, the remaining machining allowance for the grooves and slopes is 0.08 mm. After fine grinding, the remaining machining allowance is 0.04 mm. After final grinding, the remaining machining allowance for the grooves is 0.01 mm, and the remaining machining allowance for the slope is 0. The grinding wheel is a CBN270K grinding wheel, which uses cubic boron nitride abrasive with a grit size of 270 mesh and a medium-hardness (K grade). The CBN270K grinding wheel has high durability and good formability. The grinding of the grooves and straight slopes is performed on a 3MZ143 CNC bearing outer ring groove grinding machine. The stabilization treatment temperature is 135℃ and the time is 3 hours.

[0036] The process of groove finishing is as follows: the groove is finished using the dressing wheel after step one, with a finishing amount of 0.01 mm, until the surface roughness of the groove reaches 0.05 μm; the groove finishing is carried out on an SF11B finishing machine; the groove finishing uses a CBN5000ZXA oilstone;

[0037] Figure 1 This is a schematic diagram of the diamond roller structure in Example 1; the straight slope on the diamond roller is lower than the groove, and 'a' is the height difference between the straight slope and the groove. Figure 2 This is a schematic diagram of the angular contact ball bearing ring structure with grooves and a straight slope obtained in Example 1; the straight slope on the bearing ring is higher than the groove, and b is the height difference between the straight slope and the groove.

[0038] In this embodiment, the angular contact ball bearing raceway structure is a straight-slope locking structure with the straight slope higher than the raceway. Therefore, an integral grinding wheel forming and plunge grinding method are used. After fine grinding, the surface roughness of the raceway meets the design requirements, and the fine grinding amount is 0.01mm. Since straight-slope fine grinding is not performed, the raceway diameter is reduced after fine grinding, and the straight slope is higher than the raceway, meeting the locking requirements. This embodiment uses a two-cycle rough grinding and final grinding cycle, with stabilization treatment performed between the rough grinding and final grinding cycles to gradually improve accuracy and stability. The diamond roller used in this embodiment provides good consistency in the straight slope shape of the raceway, the CBN grinding wheel has high durability, and the CBN oilstone is used for fine grinding of the raceway, resulting in good formability. All quality requirements are met, significantly improving processing efficiency, increasing production capacity, and achieving a product quality pass rate of over 92%.

Claims

1. A method for combined machining of a micro angular contact ball bearing ring groove, characterized in that: The compound machining method of the raceway of the micro angular contact ball bearing raceway is carried out according to the following steps: Step one, raceway and straight slope grinding Firstly, raceway and straight slope are machined on the micro angular contact ball bearing raceway, then the diamond roller is used to trim the grinding wheel, then the trimmed grinding wheel is used to successively carry out raceway and straight slope coarse grinding, raceway and straight slope stability treatment, raceway and straight slope fine grinding, raceway and straight slope final grinding; the diamond roller has raceway and straight slope with the same shape as the bearing, the size of the raceway on the diamond roller is the same as the size of the designed raceway on the bearing raceway, and the height of the straight slope on the diamond roller is 0.005-0.01 mm lower than the lowest point of the raceway; After the raceway and straight slope coarse grinding, the machining allowance of the raceway and straight slope is 0.04-0.08 mm; after the raceway and straight slope fine grinding, the machining allowance of the raceway and straight slope is 0.02-0.06 mm; after the raceway and straight slope final grinding, the machining allowance of the raceway is 0.005-0.01 mm, and the machining allowance of the straight slope is 0. Step two, raceway lapping Oil stone is used for raceway lapping, and the lapping amount is 0.005-0.01 mm, and the raceway surface roughness reaches 0.05 μm after lapping.

2. The method of claim 1, wherein: The type of the grinding wheel in step one is CBN270K grinding wheel; the CBN270K grinding wheel adopts cubic boron nitride abrasive, the abrasive particle size is 270 mesh, and the hardness of the abrasive is medium hard (K level); the CBN270K grinding wheel has high durability and good formability.

3. The method of claim 1, wherein: The raceway and straight slope grinding in step one is carried out on a 3MZ143 numerical control bearing outer ring raceway grinding machine.

4. The method of claim 1, wherein: The temperature of the stability treatment in step one is 135 ℃, and the time is 3-4 hours.

5. The method of claim 1, wherein: The raceway lapping in step two is carried out on an SF11B lapping machine.

6. The method of claim 1, wherein: The raceway lapping in step two adopts CBN5000ZXA or CBN8000 ZXAI oil stone.

7. The method of claim 1, wherein: After the raceway and straight slope coarse grinding in step one, the machining allowance of the raceway and straight slope is 0.04-0.08 mm; after the raceway and straight slope fine grinding, the machining allowance of the raceway and straight slope is 0.02 mm; after the raceway and straight slope final grinding, the machining allowance of the raceway is 0.005-0.01 mm, and the machining allowance of the straight slope is 0.

8. The method of claim 1, wherein: After the raceway and straight slope coarse grinding in step one, the machining allowance of the raceway and straight slope is 0.08 mm; after the raceway and straight slope fine grinding, the machining allowance of the raceway and straight slope is 0.02-0.06 mm; after the raceway and straight slope final grinding, the machining allowance of the raceway is 0.005-0.01 mm, and the machining allowance of the straight slope is 0.

9. The method of claim 1, wherein: After the raceway and straight slope coarse grinding in step one, the machining allowance of the raceway and straight slope is 0.04-0.08 mm; after the raceway and straight slope fine grinding, the machining allowance of the raceway and straight slope is 0.04 mm; after the raceway and straight slope final grinding, the machining allowance of the raceway is 0.005-0.01 mm, and the machining allowance of the straight slope is 0.

10. The method of claim 1, wherein: The processing allowance of the groove and the straight slope after the rough grinding of step one is 0.04-0.08 mm; the processing allowance of the groove and the straight slope after the fine grinding is 0.02-0.06 mm; and the processing allowance of the groove after the final grinding is 0.01 mm, and the processing allowance of the straight slope is 0.

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