NTN import bearings in the precision grinding surface grinding marks

NTN import bearings in the precision grinding, due to high demand for rough, work surface grinding traces can often use the naked eye to observe its surface grinding marks mainly has the following kinds. Performance of cross helical trace reason is mainly due to the grinding wheel bus flat laymen is poor, there is concave and convex phenomenon, when grinding, grinding wheel and workpiece is only part of the contact, when the workpiece or after grinding wheel movement back and forth several times, in the workpiece will reappear cross helix and the naked eye can be observed. These spiral pitch and the size of the workpiece speed, workpiece speed, but also associated with grinding wheel axis and workbench guide rail is not parallel. ( A) 1 helix formation has a reason. Vee way bad rigidity, when grinding wheel to produce deviation, only edge grinding wheel surface contact with work; 2. Trim noisy round table when the reversing speed is not stable, accuracy is not high, a edge dressing grinding wheel is made slightly less; 3. The artifact itself rigidity is poor; 4. Have broken too peeling sand grinding wheel and workpiece under the grinding of iron product attached to the grinding wheel surface, therefore should be dressed wheel with cooling water flushing or scrub clean; 5. Grinding wheel dressing is bad, such as local protuberance. ( 2) The main reason for the spiral form 1. Grinding wheel dressing, edge chamfer, coolant not used for finishing; 2. Workbench guide guide oil too much, cause a workbench floating; 3. Machine tool accuracy is bad; 4. Grinding pressure, etc. 1, NTN import bearings tile burning: there are more iron spectrum by means of large size, alloy and black metal oxides. 2, NTN import bearings tile back micro wear: spectrum analysis found that iron concentration is unusual, there are a lot of iron in iron spectrum wear submicron particles, lubricating oil moisture and acid value anomalies. 3, NTN bearing journal import surface corrosion: spectrum analysis found that iron concentration is unusual, there are a lot of iron in iron spectrum of submicron particles, water or high acid value oil paint. 4, NTN import bearings tile surface spalling, finds many large size iron spectrum fatigue spalling alloy wear particles, the layered grits. 5, NTN import bearings surface strain: iron spectrum found cutting abrasive, abrasive ingredients for non-ferrous metal. 6, NTN import bearings tile surface corrosion: spectrum analysis found that abnormal non-ferrous metal element concentration; Iron spectrum appeared a lot of non-ferrous metal components in sub-micron wear particles; Lubricating oil excess moisture, acid value exceeds bid. 7, NTN bearing journal import surface strain: iron spectrum contains iron series cutting grinding grain or black oxide particles, metal surface heat tint.