Note - bearing knowledge of the workings of bearing inspection

Check in the operation of the transit conditions and advance the class for a thorough check program has been more and more important. And bearing as the focus of attention, because it is the most important change of all rotating parts, condition monitoring is an important part of the preventive maintenance. Early detection of bearing damage in order to avoid because of the bearing damage caused by the unscheduled equipment downtime. Especially in the important machines or harsh environment should regularly check the bearing, the current market has been quite a few systems and equipment, used to monitor the bearing, the instruments are mostly based on vibration measurement. However, not all of these instruments are equipped advanced instruments. In this case, the transfer of operators or maintenance engineers have to bearing fault signal 'maintain a high level of alert, such as noise, temperature and vibration. 'Listen', 'touch' and 'observation' are three important methods. Provided the following opinions can be used as your reference. 1, listen to use hearing to identify irregular operation is a very common method. For example, with the aid of electronic stethoscope, mechanical needles to detect a certain part of abnormal noise is often the way of experienced staff use. If the bearing is in good operation condition have a low whine, if a sharp hiss sound, make sound, as well as other irregular usually said bearing in the operation condition of bad. High-pitched squeaky noise may be caused by improper lubrication, caused by the improper bearing clearance can cause metal sound. Bearing outer ring grooves on the tracks can cause vibration and sound like the coo of a smooth. If because of the installation caused by hitting scar also can produce noise, the noise will be as the bearing rotating speed of high and low. If there is intermittent noise, said rolling parts may be damaged, this voice is happens when the damaged surface crushed out of date. Bearing inner if pollutants often causes hissing sound. Serious damage of bearing can produce irregular and big noise. Bearing damage is by listening to sleep, but usually at this time has come to the stage, the bearing must be replaced immediately so good case approach is to use such as electronic condition monitoring instrument, the workings of the diagnosis of bearing in advance. Compared with old method ( Use a wooden stick or a screwdriver in the bearing box, the other end of the stick to the ear) , the use of advanced equipment more accurately estimate the bearing condition. 2, touch the high temperature often said bearing is in abnormal state. High temperature but is also harmful to within the bearing lubricant. Sometimes bearing overheating referrible bearing lubricant, if bearing in more than 125 ℃ ( 260℉) The temperature of the running for a long time, can reduce the service life of bearing, the causes of high temperature bearing are: insufficient lubrication or excessive lubrication, lubricants contains impurities, heavy load, bearing damage, inadequate clearance and high friction produced by the oil seal and so on. So the continuity of bearing temperature monitoring is necessary, whether it is measuring the bearing itself or other important parts. If it is on the basis of the operating conditions, the temperature of any change may says it has malfunctioned. Regular bearing temperature measurement by means of temperature measuring instrument, accurate measurement of bearing temperature. The importance of bearing, means that when the damage, can cause equipment downtime, so this type of bearings shall be equipped with best temperature probe. In just under normal circumstances, bearing lubrication or lubrication after there will be a natural temperature rise and the last one or two days. 3, observation bearing if get good lubrication and can guarantee the correct cut off impurities and moisture, said oil seal should not wear. However, it is best to open the bearing box, to visual inspection of bearings and regularly check oil seal. Check of the condition of the near the bearing oil seal to ensure that they are enough to prevent hot liquids or corrosion along the axis of the liquid or gas seeping into the bearings. Protection ring and labyrinth seal grease should be applied to ensure their protection. If oil seal was worn, it should be replaced as soon as possible. The function of the oil seal in addition to prevent impurities from entering the bearing, another function is to keep lubricant in the bearing box. If oil seal oil leakage phenomenon, should immediately check whether the oil seal is already wear damage or oil plug is loose. Leakage causes may loose bearing box junction plane or formed by mixing and due to excessive lube oil leakage. Check the automatic lubrication system to ensure that the oil or grease correctly into the bearing, and to ensure that the correct amount, at the same time, examine the lubricant is color or black, if this kind of phenomenon, usually said lubricant to spoiled or contains impurities, should be replaced immediately.