The steel ball burns of sealed angular contact ball bearings are relatively easy to produce during hard grinding, which may cause soft point defects in the bearing and reduce the life of the steel ball. What should I do if the steel ball burns?
1. Sealed angular contact ball bearing steel ball line burns
Line burn means that the rolling contact point of the steel ball produces a certain friction temperature under the action of the grinding pressure and speed. When the friction temperature reaches the quenching or tempering temperature of the metal, and it is immediately cooled by the coolant, it becomes a line. Shape secondary quenching or tempering burns. There are many reasons for line burns:
1. The bell mouths of the ball divider and the grinding plate do not match, and the goal is not smooth.
Treatment method: You can adjust the ball divider and the horn of the fixed plate to make them coincide.
2. The groove of the grinding plate or the grinding wheel is deep, which affects the flexibility of the rotation of the steel ball.
Processing method: quantitative turning to process the grinding plate, automatic correction of the groove of the grinding wheel.
3. The working surface of the grinding plate and the grinding wheel is not flat or the groove depth is inconsistent, and the steel ball slips in the deep groove.
Treatment method: control the uniformity of the goal and the smoothness of the corrector to make the grooves uniform in depth.
4. The groove of the grinding plate does not match the groove of the grinding wheel.
Treatment method: After smoothing the grinding wheel, press the groove again to solve the problem.
5. The inclination of the flow ball plate is adjusted incorrectly, which makes the flow speed of the steel ball too fast or too slow.
Treatment method: adjust the angle of the flow ball to make the goal even.
6. The bell mouth of the grinding plate is too wide, so that the steel ball contacts the edge of the grinding wheel groove.
Treatment method: Control the width of the bell mouth according to the process requirements.
7. The grinding wheel is blocked by falling blocks, making the in and out of the ball not smooth.
Treatment method: Prevent the ball from the dead corner from entering, and prevent the grinding wheel groove from being too deep.
8. The ball-receiving blade has no shovel teeth or is worn into a concave shape, and the ball is not collected smoothly.
Treatment method: grinding the shovel teeth of the ball-receiving knife to make the ball-receiving more smoothly.
2. Sealed angular contact ball bearing steel ball point burn
Punctate burns are actually when the steel ball is impacted by hard points such as the fixed plate and the grinding wheel during grinding, so that the impact point on the surface of the steel ball generates a temperature. When the impact temperature reaches the quenching or tempering temperature of the metal, it will immediately When cooled by the coolant, a point-like secondary quenching or tempering burn is formed. The causes and solutions for spot burns are:
1. The speed of the grinding wheel is high, and the steel ball suddenly accelerates.
Treatment method: Control the speed of the grinding wheel in accordance with the process requirements.
2. When the grinding wheel falls off the surface of the ball, it causes a sharp increase in local pressure.
Treatment method: prevent the groove of the grinding wheel from being too deep, and prevent the ball from entering the corner.
3. The flaws of the grinding wheel groove or falling block prevent the steel ball from rolling smoothly.
Treatment method: repair or replace in time.
4. Damage to the spindle bearing of the machine tool causes the grinding wheel to swing too much.
Treatment method: check the accuracy of the spindle and repair it in time.
5. The fixed plate has sand holes, pores and hard particles, which make the local pressure on the surface of the steel ball excessive.
Treatment method: choose a good quality grinding plate.
6. The ball divider does not match the bell mouth of the fixed plate, or the ball divider retreats so that the steel ball stays at the entrance for a short time and is injured by the groove edge of the grinding wheel.
Treatment method: Adjust the ball divider and the horn of the grinding plate to anastomose, fix the ball divider firmly and strengthen the spot inspection to avoid the ball divider from retreating.
7. The scoring speed is too slow, and the number of steel balls in the groove is too small, resulting in high pressure on the steel balls.
Treatment method: adjust the speed of the material tray to make the goal even.
8. The coolant is too dirty, and the slag of the grinding wheel is not cleaned up in time to correct the grinding wheel.
Treatment method: The coolant should be replaced in time, and the grinding wheel slag should be cleaned up in time.
3. The two poles of the sealed angular contact ball bearing steel ball are burnt
In the hard grinding process, the steel ball is not in full contact with the groove of the grinding wheel, but is in contact with both sides or one side. The grinding pressure is relatively concentrated, so high temperature will be generated. When the grinding temperature reaches the quenching or tempering temperature of the metal, And when it was immediately cooled by the coolant, a bipolar burn was formed. There are two reasons for bipolar burns:
1. First, there are dead corners on the machine tool so that individual balls are normally ground into large balls, and the large balls are excessively compressed in the groove.
Treatment method: adjust the import and export, eliminate the dead corner, and avoid the dead corner ball.
2. The second is because a certain groove is blocked by foreign matter such as grinding wheel block, material head, etc., and then it is not found and removed in time, which causes the grinding wheel groove to become shallow for a long time, and two poles burn after the steel ball enters and exits the groove again.
Treatment method: use a roller screen to remove the material heads and large defective balls in the steel ball before processing; keep the coolant clean; control the groove of the grinding wheel to avoid the generation of the grinding wheel; strengthen the inspection and repair the blockage in time.
The above is all about the reasons and treatment methods for the burns of the sealed angular contact ball bearing steel balls. The above mainly deals with the reasons and treatment methods for the three different burn forms of the steel balls, such as line burns, spot burns, and bipolar burns. Explain that if you find the problem of steel ball burns during use, first determine the form of the burn, and then solve the problem in a targeted manner according to different reasons.
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