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Shanghai Shang Shaft Bearing Quality Inspection Institute Co., Ltd.

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Address: 301 Shangxue Road, Jiading District, Shanghai

Bearing Manufacturing Technology -- Grinding

2021-05-26 15:12

1  Bearing grinding, superfinishing process

Ordinary ball bearing outer ring and inner ring grinding,An example of the superfinishing process is shown in FIG. 1.

After the plastic processing and cutting processing to complete the forming processing of the workpiece, after the implementation of heat treatment, first, the reference end face is ground with a double-end grinder. Then, the outer diameter surface of the outer ring is ground by the longitudinal feed through the center-less grinding machine, which can be processed continuously.After that, the outer ring channel grinding and superfinishing are carried out on the basis of the outer ring end surface outer diameter surface. Similarly, the inner ring to carry out internal groove grinding, internal diameter surface grinding, internal groove superfine. Then submitted to the assembly, inspection process.

1.1  plane grinding

Grinding of inner and outer rings with double-end grindersBoth end faces. Double-end grinding is to correctly calibrate and assemble two grinding wheels at specified intervals, so that the ferrule passes between the two grinding wheels and grinds both ends with specified dimensions and parallelism, thus realizing continuous and high-efficiency processing.


1.2 longitudinal feed through the center-less mill

Grinding the outside of the outer ring with a longitudinal feed through a center-less grinderDiameter. The method is: Centerless grinder guide wheel, pallet and sandThe wheel supports the outer ring at 3 points, and the guide wheel rotates the outer ring,The grinding wheel rotates for grinding. Because it does not have the same as chuck processingThe center of rotation of the workpiece, so called centerless grinding,Its structure is shown in Figure 2.

Through the correct setting of grinding point, pallet support point and the angle of the guide wheel support point, to support the grinding surface for processing. At the beginning of processing, the accuracy of rough grinding is formed, the roundness of the outer diameter is gradually corrected, and the roundness of the outer ring is finally ensured. In addition, the guide wheel tilt, along the workpiece axial feed, can achieve continuous high efficiency processing.


1.3 support block centerless grinding

3 is a schematic diagram of centerless grinding of a support block. With supportThe blocks respectively support the outer diameter surface or inner groove that has been ground.The electromagnetic force adsorbs the end face to a fixture called a support plate,Grinding the outer groove or inner diameter in the state of the spindle rotation driveFace. In the spindleThe core and the workpiece supported by the support block (outer ring)Eccentricity is generated in, using the push due to eccentricity and rotation.pressure, the workpiece rotates stably on the support block. OD.The outer groove can be processed according to the constant wall thickness, and the specified groove can be obtained.The concentricity with the outer diameter and the roundness of the groove.

For the realization of the arc-shapedRgroove, to shape the grinding wheelForRshape (grinding wheel dressing), copy and work out the shape.RIn shape trimming,There areThe following methods: Replicas pre-made theirRShaped rolling wheel dresser shapes; method of dressing with a rotating single diamond dressing tool.


The inner groove is also a support block type centerless grinding, and the work.The process uses a support block to support the ground groove for grinding. BecauseIn order to support the grinding surface with a support block, it is not like the aforementioned external.As in groove grinding, it is already on the roundness reference plane,A new roundness is machined with this procedure. For fan into processing.The formation mechanism of the roundness and the centerless grinding of the outer ring.Sample, the uncentered front support block and the rear support block are equivalent to the uncentered grinder.of pallets with guide wheels.


1.4 superfinishing

4 is a schematic diagram of superfinishing of a ball bearing. Super FinePlusWork isPressing a fine-grained oilstone on a rotating workpiece(e. g. inner and outer rings), at right angles to the rotation of the workpiece.For small swing, finish the surface of the workpiece.. AsBall shaftSuperfinishing of bearing channel, isDitchRCenter for oilstone pendulumDynamic center, Processed. in addition,At the beginning, use the appropriateShould be the shape of the workpiece, because the oil stone is not implemented.Finishing, using the self-sharpening of the oil stone due to the wear of the oil stone.Use, while maintaining the shape of the oil stone, while continuing to add.Work.

The super-finished surface is a mirror surface, due to less unevenness, oilMembrane rupture is difficult, so it hasThe following characteristicsExcellent wear resistance and corrosion resistance; Due to the small processing heat generated and the thin processing metamorphic layer, the bearing capacity is high. Different from the grinding surface with intermittent cutting traces, due to the formation of continuous cuttingThe product has good mute performance.

2  Technical direction of bearing processing

2.1  Processing technology to deal with difficult-to-cut materials

In terms of grinding characteristics, the new material base with high functionalityThis is a difficult-to-cut material, resulting in poor processing efficiency, grinding wheel sharpness to maintain difficult problems. As a grinding technology adapted to difficult-to-cut materials, the firstThe first thing to mention isExpand the application of CBN grinding wheelScope.CBNGrinding wheel abrasive grain hardness and sharpness, life is better than the traditional alumina grinding wheel, suitable for difficult cutting materials, but there are dressing performance and price (high) problems, but its scope of application is gradually expanding.



2.2 processing technology to deal with environmental problems

As a kind of grinding technology which is in harmony with the environment, it isDevelopment of processing cooling lubricating fluid (coolant). Coolant is usedLubrication, cooling, cleaning and grinding of the machining partsIn most cases, heat is generated during processing, according to the surfacePrecision quality requirements, the need to use a large number of coolant. In progressThe technology developed isWith the minimum amount of coolant necessarygrinding machining, and processing using mist droplets and oil mist coolingTechnology.


To cut CO2emissions, the first countermeasures areImproving the energy efficiency of grinding machines and superfinishing machines. But,As a processing technology, such as removing the energy required for processing fromSee, grinding requires more energy than turning. Therefore,haveTo passCut grinding allowance or hard turningto cut the millCut the load, in the whole process to achieve energy saving.


2.3  Processing technology to deal with high precision

Improve the rotation accuracy of machine tool spindle bearings,To the motorBearing vibration, silenceOther requirementsHigher and higher.


To improve the rotation of the bearingaccuracy, through grinding equipmentLow vibration, high precision, optimization of grinding conditions, exclusiongrinding state interference to improve roundness, should be usedSubmicroMeter roundness of spindle bearings.


In order to achieve low vibration and silence of the bearing, improve the rolling.The super-finishing quality of the rolling surface of the moving body is conducive to greatly improving.High surface roughness and roundness, etc.


2.4  Processing technology to deal with low cost

The grinding technology of bearings is also proposed to reduce the cost.Please. Therefore,Improve the output of automatic production lines and develop lowPrice of production line equipment, production line operation of the province of human,unmanned technologyis necessary.


To increase production, it is necessary to compress the cycle time and increaseEquipment operating rate. In order to shorten the operating cycle, it is necessary to develop energy.Equipment for compressing idle time, such as loading, and developing improvedgrinding efficiency technology.


In order to improve the grinding efficiency,Using CBN grinding wheel,Taoporcelain grinding wheelThe number of examples is increasing, and this type of grinding wheel hasMoreTraditional alumina grinding wheelThe strength and sharpness of the abrasive particles.Even in the superfinishing process, it is also passing through the grinding wheel.development,Ensure reduction of grinding allowance and seek compressionProcessing time.


In addition, in order to simultaneously improve the grinding efficiency and high precision.It is necessary to achieve high rigidity and low grinding equipment.Vibration, high precision, through the function of the concentration and re-evaluation.The manufacturing process of the equipment can be developed while taking into account the low cost.And high-efficiency, high-precision equipment.


In the province of human, unmanned operating system, is.The development carried out is for the processing carried out with manpower in the past.Condition monitoring, diamond abrasive wear and mechanical thermal changeshape, can automatically handle size adjustment without manpower,A system for exchanging abrasive tools and handling abnormal equipment.


2.5 Processing Technology Adapted to Multi-variety and Less Batch Production

As a way to deal with the replacement of the device (equipment), to packageFixtures, including those carried on automated production lines.The exchange of tools and finishing devices makes it easy to improve accuracy for the purpose.The standard is being developed with careful consideration in many of the above aspects.processing equipment and production lines.


3 Summary

BearingGrinding processing environment with the processing requirements of different conditions will produce great changes,High function, high precision, low cost is the axisBearing the eternal subject of grindingEnvironmental protection is also very important.Subject.