Common knowledge of bearing maintenance
1. When checking the imported bearings that have been removed during the regular maintenance and operation of imported bearing equipment and replacing the peripheral parts, it is necessary to judge whether the sub-imported bearing parts can be reused in turn and record the use situation. It is also necessary to carefully investigate and record the removed imported bearings and their appearance. In order to find out and investigate the remaining amount of lubricating oil, the imported bearings should be cleaned after sampling.
2. Secondly, check the raceway surface, rolling surface and mating surface of the imported bearing, the wear and tear of the cage, whether there is any damage or abnormality, and especially observe the running track of the raceway surface. Judging whether the bearing can be used again depends on the damage degree of the bearing, machine performance, importance, working conditions, inspection period and so on.
Check the results. If the imported bearing is damaged or abnormal, please find out the reason according to the phenomenon of bearing damage and make countermeasures. In addition, the inspection results show that if there are the following defects, the imported bearings can no longer be used and need to be replaced with new ones.
Source: Guangzhou Schaeffler Bearing Co., Ltd. (Baidu, you will know)
2. How to repair connecting rod and connecting rod bearing?
(1) Check the connecting rod bearing for defects such as peeling or scars.
If it is damaged, please replace it with a new one. (2) Check the bending and twisting of the connecting rod with the feeler gauge on the connecting rod tester.
If the connecting rod is bent or twisted, it must be corrected or replaced with a new connecting rod. The maximum bending limit of engine connecting rod is generally 0.
05mm/ 100mm, and the maximum distortion limit is generally 0. 05 mm/100 mm.
(3) Measure the clearance of the connecting rod. First, install the plastic clearance gauge on the connecting rod journal (note that the plastic clearance gauge cannot be placed on the oil hole), then tighten the connecting rod cover with the specified torque (note that the connecting rod or crankshaft should not be rotated), then remove the connecting rod cover and check the width of the widest part of the squashed plastic clearance gauge.
If the clearance of connecting rod journal corresponding to this width exceeds the specified limit, the crankshaft connecting rod journal should be ground. Engine connecting rod bearing clearance is generally 0.
0 12~0。 090 mm.
(4) Check the axial clearance of the connecting rod. Measure the axial clearance between connecting rod and crankshaft with a feeler gauge.
When measuring the axial clearance, first press the connecting rod to either side of the crankshaft, and then measure the clearance on the other side. If the axial clearance of the connecting rod exceeds the specified value, replace the connecting rod and/or crankshaft.
The axial clearance of engine connecting rod is generally 0. 13~0。
38 mm.
3. How to repair the rolling bearing?
Rolling bearings are mass-produced mechanical parts, which require very strict manufacturing accuracy and have a very high degree of technical specialization. Therefore, for most bearings that are easy to buy, buying should save more money than repairing. Only in the following cases will bearing repair be considered, that is, (1) a large number of bearings of the same model used in large factories, and their failure forms are mainly wear, fatigue or fretting of rolling surfaces, especially the damaged parts are mostly cages or fretting. (2) Large and extra-large bearings are on the verge of failure, or have failed without major damage to parts, or expensive bearings must try to extend their effective service life; (3) Some bearing varieties that are really hard to buy have to be repaired without spare parts after failure, especially imported bearings; (4) The bearing is slightly damaged, such as slight water rust during storage and slight fretting wear during transportation, which is easy to repair and a pity to discard.
Bearing repair is not only economical, but also technical, which requires the repairer to fully understand the corresponding technical requirements of the bearing and the structure, technology and material characteristics of the bearing and its parts, otherwise it will be difficult to ensure the required effect of bearing repair. First, the economic benefits of bearing repair Generally speaking, bearings are few in variety and large in quantity, and the price of a single bearing is high, or the bearing structure is simple.
The larger the size, the lower the repair cost and the higher the economic benefit. In addition, it can get twice the result with half the effort to monitor the operation of the bearing and carry out planned maintenance before the bearing fails.
Following reasonable technology, using efficient repair equipment and tools, and getting help from professional bearing factories are all helpful to improve economic benefits. Second, the benefits of cooperation with professional bearing enterprises In the business of repairing bearings, if users can get the cooperation of professional bearing enterprises, they may get the following benefits: (1) They can clarify the technical requirements of each repair process and how to ensure the overall quality of the repaired bearings; (2) Be able to use many professional experiences of professional bearing factories to meet technical requirements reliably, efficiently and economically; (3) You can order a number of dies from a professional bearing enterprise and borrow them for maintenance, which may be more economical and save a lot of trouble; (4) You can order cages, rolling bodies, rivets and other accessories from professional bearing enterprises, which may make the repair work simple, convenient and economical.
4. What are the maintenance methods, procedures and quality standards for rolling bearings?
(1) Remove the lubricating oil and clean the bearing with gasoline.
(2) Rotating the bearing by hand should be flexible without jamming and noise. The surfaces of the inner and outer rings of balls, rollers and raceways are smooth, without cracks, rust spots, peeling scars and mechanical deformation.
Otherwise, the bearing should be replaced. (3) Check the cage for cracks, deformation and corrosion, and fasten the rivets.
When the steel cage bearing is placed vertically, (4) measure the inner diameter of the bearing inner ring, the outer diameter of the bearing outer ring and the dimensions of the shaft and bearing sleeve to ensure a proper tight fit.
Generally, the outer ring and bearing sleeve can be matched zero to zero; Both the inner ring and the shaft diameter need a certain tightening force. The tightening force is based on the principle that the bearing is installed and can rotate freely and flexibly. The larger the shaft diameter, the greater the fastening force, and the smaller the shaft diameter, the smaller the fastening force. For example, the assembly tightening force of a bearing with an inner diameter of 120mm is 0.0 1? 0.02_ is preferred. Otherwise, if the fit is not tight, the bearing should be handled correctly.
5. How to maintain the bearing?
A, bearing maintenance:
1. Improve lubrication quality, control oil pressure, temperature and flow, and strengthen oil filtration.
2. Use fuel and lubricating oil that meet the requirements.
3. The diesel generator set should not control the temperature state and work under the conditions of supercooling and overheating. In cold weather, the diesel engine should be warmed up before starting, and the crankshaft should be turned by hand to make the oil enter the friction surface.
4, bearing and journal surface quality and geometry should be strictly guaranteed.
5, bearing clearance should be appropriate, the generator set is too large to produce impact, too small is poor lubrication, may burn tiles.
Second, the bearing maintenance method:
1. When removing the bearing for inspection, make a good appearance record by taking photos and other methods. In addition, before cleaning the bearing, it is necessary to confirm the amount of remaining lubricant and sample the lubricant.
(1) Bearing cleaning can be divided into rough cleaning and fine cleaning, and metal grids can be placed at the bottom of used containers.
(2) In the process of rough washing, use a brush to remove grease or sticky substances from the oil. At this time, if you rotate the bearing in oil, be careful that the rolling surface will be damaged by foreign objects.
(3) During fine washing, slowly rotate the bearing in the oil, which must be carried out carefully. The cleaning agent usually used is neutral non-aqueous diesel oil or kerosene, and sometimes warm lye is used as needed. No matter what kind of detergent you use, you should always filter it to keep it clean. Immediately after cleaning, apply antirust oil or grease to the bearing.
2. Inspection and judgment: In order to judge whether the removed bearing can be reused, the dimensional accuracy, rotation accuracy, internal clearance, mating surface, raceway surface, cage and sealing ring should be emphatically inspected. Because large bearings cannot be rotated by hand, attention should be paid to the appearance of rolling bodies, raceway surfaces, cages and retaining surfaces. The higher the importance of bearings, the more you need to check them carefully.
Extended data:
Quality inspection of bearings;
1, is the packaging clear? Generally, brands produced by regular manufacturers have their own special designers to design the outer packaging and arrange factories with production conditions for production. Therefore, the packaging of products should be very clear and unambiguous from lines to color blocks.
2. Is the steel seal clear? Every bearing product will be printed with its brand words, labels and so on. Although the font is very small, the products produced by regular manufacturers are printed with steel printing technology, and they are pressed before overheating;
So although the font is small, it is deep and clear. Usually, the fonts of counterfeit products are not only vague, but also float on the surface due to rough printing technology, and some of them can even be easily erased by hand, or there are serious manual marks.
3. Whether there is noise: Hold the bearing inner sleeve with the left hand, and move the outer sleeve with the right hand to make it rotate, and listen to whether there is noise during the bearing operation. Due to the backward production conditions of most counterfeit products and completely manual workshop operation, impurities such as dust and sand will inevitably be mixed in the bearing body during the production process;
Therefore, when the bearing rotates, there will be noise or unsmooth operation. This is the key to judge whether the product comes from the brand products of regular manufacturers, which have strict production standards and machine operation.
4. Surface: Whether there are turbid oil stains on the surface requires us to pay special attention when buying imported bearings. Because there is still a certain gap between domestic anti-rust technology and foreign advanced manufacturing countries, it is easy to leave thick oil stains when the bearing body is treated with anti-rust, which makes it feel sticky by hand.
However, almost no traces of antirust oil can be seen on bearings imported from abroad. According to insiders, people who are particularly careful can smell a special smell on imported bearings, that is, the smell of antirust oil.
5. Whether the chamfering is uniform: The so-called chamfering of the bearing is the joint between the horizontal plane and the vertical plane. Due to the limitation of production technology, counterfeit bearing products are not handled satisfactorily at these corners, which is easy for us to distinguish.