During the grinding process of the bearing, the working surface of the bearing is ground by a high-speed rotating grinding wheel. Therefore, if the operation and adjustment of the equipment are not carried out according to the operation instructions during grinding, various roughness will appear on the working surface of the bearing. Degree defects, so as to affect the overall quality of the bearing. When the bearing is precision ground, due to the high surface roughness requirements, the grinding marks on the working surface can often be observed with the naked eye. The grinding marks on the surface are mainly as follows. (It is recommended to use a roughness tester for the detection of roughness) The reason for the appearance of crossed helix traces is mainly due to the poor straightness of the busbar of the grinding wheel and the existence of concave and convex phenomena. During grinding, the grinding wheel and the workpiece are only partially in contact. After the workpiece or grinding wheel is moved back and forth several times, the cross helix is u200bu200breproduced in the performance of the workpiece and can be observed by the naked eye. The pitch of these helical lines is related to the speed of the workpiece table and the rotational speed of the workpiece, as well as the non-parallel relationship between the axis of the grinding wheel and the guide rail of the table. (1) The main reasons for the formation of the helix 1. The grinding wheel is not properly trimmed, the corners are not chamfered, and the coolant is not used for trimming; 2. The guide rail of the worktable is too much lubricating oil, causing the worktable to float; 3. The machine tool accuracy is not good ; 4. Grinding pressure is too large, etc. (2) There are reasons for the formation of the spiral line: 1. The rigidity of the V-shaped guide rail is not good. When grinding, the grinding wheel is offset, but the edge of the grinding wheel is in contact with the working surface; ;4. The diamond fastening frame is not firm, the diamond is shaken or the quality of the diamond is not good and not sharp; 5. The hardness of the grinding wheel is uneven, etc. The main reason for the reappearance of scratches on the working surface is that after the coarse-grained abrasive grains fall off, the abrasive grains are sandwiched between the workpiece and the grinding wheel. The specific reasons why the surface of the workpiece is rough during grinding are: 1. The traces left during rough grinding are not ground during fine grinding; 2. The coarse abrasive particles and tiny abrasive particles in the coolant are not filtered cleanly; 3. Coarse particle size When the grinding wheel is just dressed, the abrasive grains are easy to fall off; 4. The toughness of the material is valid or the grinding wheel is too soft; 5. The toughness of the abrasive grains and the toughness of the workpiece material are not matched properly. There are straight wave traces on the surface of the workpiece. We cut a cross-section of the vertical axis of the ground workpiece and enlarged it, and we can see that its periphery is similar to a sine wave. If its center has no rotation and translation along the axis line, the trajectory around the sine wave is a waveform cylinder, which is also called a polygon. The reason for the straight waveform is the movement of the grinding wheel relative to the workpiece or the periodic change of the grinding pressure of the grinding wheel on the workpiece, which causes vibration. This vibration may be forced vibration or self-excited vibration, so there are often more than one straight wave frequency on the workpiece. The specific reasons for the straight wave traces are: 1. Too much clearance of the grinding wheel spindle; 2. Too high hardness of the grinding wheel; 3. Poor static balance of the grinding wheel or dullness of the grinding wheel; 4. The workpiece speed is too high; 5. The lateral knife is too large 6. The grinding wheel spindle bearing is worn, and the matching clearance is too large, resulting in radial runout; 7. The grinding wheel pressing mechanism or the worktable is crawling, etc. The surface of the workpiece reproduces burn marks. The surface of the workpiece is often burned during the grinding process, and there are several types of burns. Types, one is that the burn is along the machining direction of the grinding wheel, which is a dark black patch; the other is that it is in the shape of lines or intermittent lines. The surface of the workpiece is burned during the grinding process, which can be summed up for the following reasons: 1. The grinding wheel is too hard or The particle size is too fine and the structure is too dense; 2. The feed rate is too large, the supply of cutting fluid is insufficient, and the heat dissipation conditions are poor; 3. The speed of the workpiece is too low, and the speed of the grinding wheel is too fast; 4. The vibration of the grinding wheel is too large, and the grinding depth occurs continuously Changes and burns; 5. The grinding wheel is not dressed in time or not well; 6. The diamond is sharp, and the grinding wheel is not well dressed; 7. The workpiece is burnt too deeply during rough grinding, and the fine grinding allowance is too small, and it is not ground off; 8. The workpiece Insufficient clamping force or suction force, under the action of grinding force, the workpiece has stopped rotating, etc. So how does the workpiece surface know whether it is burning during the grinding process? This can be checked by regular pickling. After that, when the surface is wet, it should be visually inspected under the astigmatism light immediately. The normal surface is uniform dark gray. If it is a soft spot, it will appear cloud-like dark black spots, and the perimeter is not fixed; if it is decarburized, it will appear gray or dark. If the grinding process cracks, the cracks will be in the shape of cracks. If it is burned, one is that the surface shows dark black plaques along the machining direction of the grinding wheel, and the other is lines or intermittent lines. It is necessary to analyze the reasons in time, take effective measures to solve it, and prevent batch burns. The surface roughness of the bearing parts does not meet the requirements. The surface roughness of the bearing parts has standards and process requirements, but in the process of grinding and superfinishing, Due to various reasons, the specified requirements are often not met. The main reasons for the surface roughness of the workpiece not meeting the requirements are: 1. The grinding speed is too low, the feed speed is too fast, the feed amount is too large, and there is no feed grinding The cutting time is too short; 2. The workpiece speed is too high or the vibration of the workpiece shaft and the grinding wheel shaft is too large; 3. The grain size of the grinding wheel is too coarse or too soft; 4. The dressing speed of the grinding wheel is too fast or the clearance of the dressing mechanism is too large; The diamond is not sharp or the quality is not good; 6. The quality of the super-fine oil stone is not good, and the installation position is not correct; 7. The quality of the super-fine kerosene does not meet the requirements; 8. The super-fine time is too short, etc.; as long as we strictly follow the operation instructions The book is carefully operated and inspected, and the cause of the problem is analyzed and solved in time. These defects can be avoided, thus ensuring the overall quality of the product.