| Home>Bearing knowledge>About: the application of self-smooth bearings in casting |
Talking about the application of self-smooth bearing in casting
Source: Bearing network time: 2014-09-21
| /*250*250 was created on 2017/12/25*/ var cpro_id = 'u3171089'; |
The aluminum liquid produced by the aluminum electrolytic cell is sucked out by vacuum lifting and poured into the mixing furnace; after being proportioned and slag removed; flowing into the aluminum ingot casting machine for casting; the solid formed is called aluminum ingot; The aluminum ingot is stacked by the stacker. In order to improve the production power; it is necessary to use a lot of cooling water for cooling before the aluminum ingot is formed; during the cooling process, the large thermal energy of the aluminum liquid is released into the cooling water; hot water vapor occurs.
v Casting machine bearings are in the high temperature water vapor environment; many bearings are smooth grease; the added smooth grease will be melted and overflowed due to high temperature in a short time; protection and protection is difficult; equipment cleaning is also difficult to wipe The steel layout bearing is very simple and corrosion rust in hot and humid environment; the failure rate is very high; the equipment repair cost is high; the equipment operation is often confused by the following two problems.
It is difficult to complete the high-temperature continuous operation of the oil supply operation. The ingot, the ingot, the ingot, the ingot and other equipment of the casting machine are installed in the unit casing; each of the conversion bearings is marked with a nozzle device that is regularly written with smooth grease; Parking removes the casing; presses the grease with a grease gun. And the machine has more than 30 oil filling points; long-term operation protection can not complete this cumbersome oiling operation; it is only necessary to hold the oil bottle in the operation of the bearing Set of exterior; smooth oil is difficult to enter the conflicting side of the bearing; most bearings are in conflict.
The ambient temperature is high; the grease is smooth and not used to the molybdenum disulfide smooth grease used in the current casting machine rolling bearings. It is known as the high temperature grease; we know that its base oil is a petroleum product; plus a few high temperature resistant molybdenum disulfide increase agent; The temperature limit is also 120 ° C. It is estimated that the casting machine bearing operating temperature can reach 200 ° C; has far exceeded the smooth grease temperature limit.
Under such high temperature conditions; the base oil in the smooth grease will become thinner and gradually transpire; the remaining carbon residue, molybdenum disulfide and dust will be mixed into a solid block to condense on the support frame of the rolling bearing; not only the smoothing effect is lost; It also prevents the normal operation of the rolling bearing and wears out quickly; it can be stopped for up to 2 weeks; the bearing is removed to remove the new grease.
I. Wear situation The abnormal wear of the bearing caused by the two major problems in the bearing operation of the aluminum ingot casting equipment is more severe. Take the aluminum alloy ingot structure as an example; the bearing has a uniform service life of 2 months; when the wear is severe, it will actually be 5MM. The inner ring wears through; the equipment cannot continue to work.
The wear is uneven. The reason is that the original oil supply method can not be completed; the outside of the bearing in the operation has to be smelted with thin oil; a few can be leached into the bearing; the wear is more than 50% of the The shaft and sleeve are not smoothed; but in the case of dry conflicts, strong adhesive wear occurs. This wear quickly increases the gap between the shaft and the sleeve; the dust is more accessible; it constitutes a vicious circle.
Second, the choice of oil-free self-smooth bearing in order to deal with the high temperature, low speed, heavy load, dust, water shower and shock oscillating smooth problems in mechanical equipment; the choice of oil-free self-smooth bearings.
1. The layout of the bearing from the smooth bearing is to develop the appropriate holes in the metal collision surface of the bearing matrix; and embed the molybdenum disulfide, graphite and other composite self-lighting sliders embedded in the metal sleeve; Composite bearing; solid smoothing agent friction area of ​​25-65%. Solid self-lighting slider can work normally at 280 ° C high temperature. However, due to its low mechanical strength; load bearing ability is weak; easy to deform; it is embedded in metal The defect can be pressed in the hole groove; the metal is formed to bear some bearing effect; the smoothing effect from the light slider.
The smooth mechanism of this self-smooth bearing is in the process of the sliding conflict between the shaft and the sleeve; a part of the smooth material is transported to the metal appearance of the shaft; the small flat surface is filled; and a stable solid smoothness is formed. Membrane; constitutes a solid smooth film between the grinding; avoids the adhesion between the shaft and the sleeve. This rationality summarizes the complementary strengths of the copper alloy and the non-metal grinding data; uniquely suitable for oil-free, high temperature, high load Low speed; anti-fouling, anti-corrosion, moving range in strong radiation environment; and special working conditions under the condition that the water or other solution is moisturized and the bottom is unable to add smooth grease.
2. The area occupied by the self-lighting slider is related to the working speed and bearing strength of the self-lighting slider; the operating speed is low, the bearing strength is large; the area occupied by the metal should be larger. The area of ​​the traveling wheel bearing from the light slider is about 25%; the bearing of the pulling spindle is smooth and plentiful; the bearing strength is not large; the area occupied by the light slider is about 65%.
3, the technical requirements of the bushing material bushing should be made of alloy copper; the bushing should have a higher hardness; usually heat treatment; its hardness is not lower than HRC45.
4. Several shapes and inlay requirements of the self-lighting slider. The shape of the self-lighting slider has two kinds of cylindrical shape and rectangular shape; the self-smoothing can be selected from the cylindrical shape according to the size of the area; instead, a rectangular shape can be used. Inlaid and strong; to prevent falling in the work.
5. Cooperating gap value between bushing and shaft The linear expansion coefficient of the self-lighting slider is about 10 times that of steel. It is the change of custom bearing temperature; the gap between shaft and bushing is four-stage dynamic cooperation of original metal parts (D4/DC4) 0. 032 ~ 0. 15MM; increased to 0. 45 ~ 0. 5MM. From the light slider on the side of the conflict, the outstanding bushing metal 0. 2 ~ 0. 4MM. This will be abundant in the initial running-in period of the bearing operation Smooth; cut the cost of power drag power.
6, oil-free from the strength of the smooth bearing A, no oil smooth or less oil smooth; suitable for places that can not be refueled or difficult to refuel; can be used in the protection or less protection,
B, good wear resistance; conflict coefficient. lemon 倜ムC, excessive elastoplasticity; can spread the stress on a wider touch surface; improve the bearing capacity of the bearing,
D. Near the static motion conflict coefficient; can eliminate the flaw at low speed; then ensure the accuracy of the machine operation,
E. It can make machinery reduce oscillation, reduce noise, avoid pollution; improve working conditions,
F. It can form a carrying film during the operation; it can protect the shaft from grinding;
G. The hardness requirement of the grinding shaft is low; the unscheduled shaft can be used; then the processing difficulty of the associated parts is reduced.
H, thin wall layout, light weight; can reduce mechanical volume,
I. The bushing material is brass; it can be used in corrosive media.
After the theory of an aluminum company; the casting machine bearing changed to oil-free self-smooth bearing; it has been used for 15 months; and still working; the gap between the shaft and the bushing does not exceed 1MM; it is estimated that it can be used for another 12 months; Beyond the original life of the application (2 months).
Oil-free self-smooth bearings can not only be used well in aluminum ingot casting machines; they can be used together without oil, high temperature, high load, low speed; anti-fouling, anti-corrosion, moving radiation in strong radiation environment; and in water Or equipment under special working conditions where the solution is moisturized and the base cannot be smoothed; such bearings have a wide range of implementation values.
At present, most of the bearings used in various machinery industries are still balls, needles and the like; but some have chosen self-smooth bearings; trust will soon come from smooth bearings will become the dominant bearing. The following are some of the characteristics of self-smooth bearings. And advantages:
1, no oil smooth or less oil smooth; suitable for places that can not be refueled or difficult to refuel; can be used without protection or less protection,
2, good wear resistance; conflict coefficient. Lemon 倜ム3, excessive elastoplasticity; can spread the stress on a wider touch surface; improve the bearing capacity of the bearing,
4. Near the static motion conflict coefficient; can eliminate the flaw at low speed; then ensure the accuracy of the machine operation,
5, can make machinery reduce oscillation, reduce noise, avoid pollution; improve working conditions,
6. It can form a carrying film during the operation; it can protect the shaft from grinding;
7. The hardness requirement of the grinding shaft is low; the shaft that has not been tempered and treated can be used; then the processing difficulty of the associated parts is reduced.
8, thin wall layout, light weight; can reduce the mechanical volume,
9, the reverse side of the steel can be electroplated with a variety of metals; can be used in corrosive media, has been widely used in various mechanical sliding parts; for example: printing presses, textile machines, tobacco machinery, micro-motors, automobiles, motorcycles and agricultural and forestry machinery and many more.
Recommend to friends comments close window
| Bearing related knowledge |
| Bearing type suitable for selecting projects to analyze the common terms and definitions of rolling bearings (2) Correcting the bearing's fundamental additional dynamic load according to the temperature The reason for the increase of NTN bearing temperature and the corresponding treatment method |
This article links to http://
Please indicate China Bearing Network http://
Previous:The five major issues that need to be paid attention to in the bearing work: The following is a common vocabulary of machinery (13)
Electronic Chemicals,99.8% Cas 7553-56-2,Iodine Crystal 99.8% Cas 7553-56-2,Iodine Crystal 99.8%
HENAN BON INDUSTRIAL CO.,LTD , https://www.bonchemical.com