SKF four row tapered roller bearing abnormal damage - inner
2018-01-15
. Bearing structure and characteristics.
380000 this kind of bearing structure is compact, basic performance and double row circular cone roller bearings basic same, can withstand the radial and axial joint load, the basic structure consists of two double row inner ring components (rolling body, cage and inner ring) and a double outer ring and two single outer ring and two side baffle, an inner circle of insulation.
In the outer ring, inner circle and inner and outer rings are printed with character symbols, and the bearing boxes must be packed in the order of character symbols.
Do not interchangeably to prevent the change of bearing clearance.
1. Assembly method.
Type 1, four row tapered bearing is separable bearing, the outer ring, baffle, and the rolling body components (rolling element and cage and inner ring), when the assembly installed in turn edge of outer ring - A, roller components outside baffle - A, AA, in the outer ring, inner space ring, rolling body components - E, separated from BB last edge of outer ring - E all installed the case such as bearings, bearing box then press on the gland
Bearing load bearing body work is done, the entire assembly order, in addition to the appeal must be installed in the gland step as the core, must guarantee gland effectively pressure on end face and the bearing outer ring end face, namely, can't give too much pre-tightening force caused by prestressing force to prevent bearing outer baffle deformation caused by bearing installed the game changes, and can't appear too big axial clearance, must guarantee gland end with bearing end face, usually after the end of the mouth come into contact with the bearing section need to measure (gauge) gland and bearing the gap of end face of the S value, and then add appropriate thickness adjustment gasket to ensure gland with bearing face, gasket (rigid) thickness H = (S + 0.05).
However, four rows of tapered roller bearings are equipped with high C value, and the deviation is larger, generally exceeding 0.5mm, which means that each assembly must be measured to ensure the cooperation between the gland and the bearing end.
2. bearing assembly to bearing box, and then lifting (bearing inner ring with roller diameter clearance fit) directly to the bearing suits at the end of the roll diameter through the whole bearing axial locking ring precise locking on the roll, thus forming bearing box, a combination of roller and bearing assembly.
Iii. Bearing damage form.
. The bearing is often damaged by the third column and the second column after it is burned, which also corresponds to the damage of the cage and outer ring.
. Phenomenon analysis.
Comprehensive bearing characteristics, the installation process and damage phenomenon, can be analyzed, when the rolling bearing axial force of the two directions, when the axial force from one side passed, bearing axial force, respectively is a third column under axial force in one direction, by 2/4 columns under axial force in one direction, and from the picture and two-thirds of the bearing damage rule column is easy to damage, which means the bearing during operation, when the axial force passed not two columns of the scroll body at the same time bear the axial force of a direction, but the anomaly of single row bearing, resulting in the bearing axial load drop 50%, will inevitably lead to abnormal loss of bearing.
Further analysis the cause of single row bearing and the bearing structure can be analyzed out, only bearing assembly error or baffle in height after wear, will cause the axial force transfer blocking, causes the single roller bearing, so check the damaged bearing inner circle, found space ring wear.
At this point, it is concluded that the abnormal damage of the bearing is caused by the shorter wear in the system, which causes the axial force transmission to be blocked, causing the bearing damage caused by the single column force.
And the wear of the inner ring is mostly due to the outer ring and pressure cover not pressed, the gap is too large and the lubrication effect is poor.
. rectification measures.
1. Improve the hardness of the inner ring of the bearing.
2. Strengthen the lubrication measures at the diaphragm.
3. Improve the assembly precision, and make sure to assemble the measurement once.