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the article citations: time:2014-12-16 10:52:08
machine tool shaft parts, especially the main shaft, generally and thrust ball bearing assemble into an organic whole, and rotate at high speed, can sometimes produce high heat. if not promptly eliminate, this phenomenon will cause the overheating, and makes the corresponding parts temperature rise and thermal deformation will occur, serious when they make the main shaft and tail frame range is high, which not only affect the accuracy and machining accuracy of machine tool itself, but also the bearing burn out.
rated fatigue life, it is to point to a set of the same type of bearing, in the same conditions, 90% of the angular contact ball bearing is not appear fatigue spalling caused by the total number of turns. when the rotating speed is constant, multi-purpose total run time rated fatigue life.
when research thrust ball bearing life, not only consider the fatigue life, but also according to the performance of the bearing should have comprehensive several use limit to consider. for example, the grease lubrication grease bearing life. life and wear life, noise, according to different purposes, using different limit benchmark, so, mostly chosen in advance experience.
therefore, only survey damage, the real reason is hard to come by injury. but, if you know the use of thrust ball bearing machinery, conditions of use, bearing the surrounding structure, to get hold of before and after the accident, combined with several damage status and causes of bearing, can prevent the similar accident happen again.
is available, mainly considering bearing damage degree, mechanical properties, importance, and operating conditions, to the next overhaul period. if there are the following defects can't use, must replace the new thrust ball bearing. inner ring and outer ring, rolling element and cage on any one have crack or gap.
wear failure is one of the common failure modes of all kinds of bearings, according to the wear and tear is usually divided into one of the most common form of abrasive wear and adhesive wear.
1. the oil film resistor diagnostic technique
features: can use the same criteria for different working conditions. the surface spalling, indentation and crack the diagnosis of abnormal effect is poor.
application range: applicable to the axis of rotation exposed.
2. the vibration diagnosis technology
features: vibration diagnosis technology widely used; can realize on-line monitoring; diagnosis, diagnosis theory has been mature.
application: apply is especially suitable for angular contact ball bearing in the rotating machinery fault monitoring.
3. the ferrographic diagnosis technology
characteristic: the machine without disintegration; low investment and good effect; can be found without oil bearing early fatigue failure; can do wear mechanism research.
application range: applicable to oil lubrication of angular contact ball bearing fault diagnosis, with grease lubricated bearings is difficult.
4. temperature diagnosis technology
features: simple diagnosis; for bearing burn judgment effect is better.
application range: applicable to the machine simple routine diagnosis of bearing.
5. optical fiber monitoring and diagnosis technology
features: high sensitivity optical fiber displacement sensor; directly from the oilless bearing surface to extract the signal and improve the signal-to-noise ratio; can directly reflect the manufacturing quality of angular contact ball bearing, the degree of surface wear, load, lubrication and clearance.
application range: applicable to the sensor can be installed on the bearing seat inside the machine.
6. acoustic emission diagnosis technology
features: diagnosis of quick, easy; can online monitoring.
application: in recent years the development of new technology, less used in bearing condition monitoring.
directly take oilless bearing, with the hand to wash hands fully the sweat, and again after coated with high quality mineral oils, especially in the rainy season and summer to pay attention to rust. in some special operating conditions, can get more than the life of the traditional computing, especially in the case of light load. the operating conditions of these special is, when the rolling surface (orbit and rolling) is a lubricating oil film effectively separated and the surface of the limit of pollutants may cause damage. in fact, under ideal conditions, the so-called permanent bearing life is possible.
do not allow the powerful punch, are not allowed to use hammer percussion bearing directly, don't allow through the transfer roller pressure.
a rotation, inner ring and outer ring raceway surface, with rolling body is rolling contact, as the dark side, thus orbit trajectory are attached to the raceway surface does not belong to abnormal, which can be learned that load conditions, so when removing oilless bearing, please keep close attention and observation on the surface of the raceway.
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