preload preload preload preload

Judge ntn corner exposed to trouble of ball bearing damage and adjust the preloading method


12th December 2013 Bearing Technology 0 Comments

From peeling off, impression, corrosion, crackle, abrading,etc. will reflect seeing in the vibration measurement of the bearing, it is very responsive that ntn bearing shakes the damage to the bearing, so, the angle contacts the ball bearing through adopting the special bearing to shake the measurer frequency analyser,etc. Can measure the vibrating magnitude, assign to and can’t educe the out of order detailed conditions through the frequency. Different because of using the sensor erection site of conditioned disjunction to wait for of the bearing because of number values that is measured, so need to analyze to the measured value of each machine that compare, confirm the judgement criteria in advance.

Because even ntn bearing has slight stripping etc. to damage, will pronounce unusual sound and irregular sound, can go on, distinguish with acousimeter, adopt acousimeter, exposed to ball bearing, roll acoustic magnitude and tone quality, come on, go on, check to horn in the operation, play a role in preventing ahead of time.

Enable oil hole the intersection of direct measurement and the intersection of bearing and the intersection of outer lane and temperature, is suitable. Generally speaking, the intersection of ntn and temperature of bearing, temperature outside the general the intersection of basis and bearing room can infer that came out. If lubricate, install one is suitable, then the bearing is warm will all be urgent to rise suddenly, the high temperature that will become abnormal, must shut down at this moment, take the essential precautionary measures. Usually, the temperature of the bearing is with operating beginning to rise slowly, reach the stable condition 1-2 hours later. The angle is exposed to the normal temperature of the ball bearing because of the heat capacity of the machine, the quantity of heat dissipation, rotational speed and supporting but different. If necessary, use the operating temperature that the thermal sensor can monitor the bearing at any time, autoalarm family at the time of the specified value that the temperature of concurrent implementation exceeds or stopping preventing firing the axle accident and happening.

The assembly of ntn bearing is assembled by the bench hand and elementary operation in the repair work, and adjustment and preloading of backlash are the important links of fitting work of the antifriction bearing. Hold the craft concepts of backlash adjustment and preloading accurately, and use this kind of technique in fitting work correctly, it is the assurance of the bearing assembly workmanship.

The backlash of ntn bearing refers to the maximum activity that another collar does radially or axially under the stationary situation of a collar, so the backlash is divided into two kinds radial backlash and axial backlash again. When the angle contacts the ball bearing to assemble, the backlash can’t be too big, it can’t be too small either. The backlash is too big, will cause and bear the loaded quantity of rolling element to reduce at the same time, the load of the single rolling element increases, thus reduce the rotatory precision of the bearing, reduce the life time; The backlash is too small, will make frictional force increase, the heat that produces increases, aggravate the abrasion, can make the life time of the bearing reduce too. So, the bearings all want the rigid control and adjust the backlash during assembly.

Preloading is a bearing during assembly, a axial force of inner circle or outer lane that give, so as to dispel the intersection of bearing and backlash, and it is out of shape at the beginning to enable the rolling element keep in touch, produce with the inner, outer lane. Preloading can improve bearing rigidity and rotation precision in working condition, bear load to be relatively large, rotate accuracy requirement higher bearing, large to have, work under the state that drib full of even in backlash of having, in this case need to carry on preloading to the bearing in assembly. Usually enclose the method to do appropriate axial relative displacement to finish to the outside through the inner circle in adjustment and preloading of the backlash. It is easy to find out, are exposed to the adjustment of the backlash of ball bearing through the opposite angle from the above-mentioned technology concepts, can improve bearing capacity and rotation precision of the bearing, raise the life time of the bearing. But will aggravate ntn bearing friction at the same time, the calorific power increases, so must guarantee the good lubrication and dispel the heat while adjusting the backlash or preloading. If it is improper to change or lubricate badly, will aggravate bearing wear conversely, the life-span is reduced. Carry on adjustment and preloading of the backlash of bearing correctly, should pay attention to the following questions.










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