Tapered roller bearing: Bearing expert why burned or locked
Shaft tolerance is relatively small and fine head, the inner shell inside and nose has obvious signs of friction. If there are traces of friction on one side or on both sides of the inner shell, there is an abnormal contact with the inner shell of the bearing and the friction of the inner shell of the bearing.2, the inner shell shell burning marks are not serious, roller black even deformation, generally is the inner shell or casing tolerance, Ambassador bearing gap smaller, and even negative tolerance caused by burning. Or in the maintenance of the bearing selection is not correct, you can use large clearance bearings.3, the shell burned seriously, the inner shell, roller are no obvious changes, you can observe whether the shell has traces of friction. There are traces of friction on the outside, and it can be considered that the tolerance between the bearing shell and the shaft is insufficient, which results in abnormal friction caused by the slipping of the housing. If there are traces of friction on one side or on both sides of the shell, there is an abnormal contact between the component relative to the bearing housing and the bearing housing, and the heat generated by friction will be burned out.
2, the bearing seat hole size deviation is too small or the size of the shaft deviation is too large, extrusion bearing ring deformation, make the clearance smaller. To burn locking phenomenon.3, bearing outer diameter and bearing seat hole, or between the bearing bore and the surface of the shaft between the foreign body, such as iron filings, burr, sand, cotton and so on. Will also squeeze bearing deformation, so that smaller clearance. To burn locking phenomenon.Bearing burnt lock. The cause of the accident can be analyzed according to the burning degree of the inner shell, the outer shell and the roller1. The inner shell burns most severely, the roller slightly lighter, and the outer shell almost does not change. After excluding the reasons for the nonstandard size of the inner bearing housing, the following judgment can be made.
1, improper choice of bearing clearance.For example: C3 group should be selected for clearance, and the actual use of ordinary group clearance. Because when the bearings work will continue to accumulate heat, shaft diameter and inner ring and outer ring rolling body will swell, because good radiating condition of expansion is relatively small, the whole bearing clearance becomes small, or even negative clearance larger.At this time, stress increases between the body and the rolling roller pressure, lubrication conditions decreased, there will be the phenomenon of boundary lubrication or even local steel on steel friction, so the temperature continues to rise, the base oil in lubricating grease evaporation, so lead to vicious spiral bearing overheating burned, rolling annealing into blue black color, then bearing the friction increasing roller holder to stop COLLOPSE bearing lock.
