Self-lubricating bearings used in the aluminum ingot casting machine

   Wide temperature self-lubricating bearings, solid lubricant content sufficient to release even with good self-lubricating properties and seizure resistance, can effectively protect the journal achieve lasting purpose. Suitable for high temperature, low speed, heavy, dusty, run under water shower and there is shock and vibration environment, can be widely used in mining machinery, metallurgy, petroleum, chemical, food, textile, paper making, printing and dyeing machinery and equipment rolling and plain bearing parts.
 
   Aluminum electrolysis cell to produce aluminum ingot, after sucked out by a vacuum ladle furnace is poured into a mixed, after the proportion and slag flowing into the aluminum ingot casting machine casting molding, molding solid called ingots, aluminum production ingot by the stacker stacking. In order to improve production efficiency, must be pre-molded aluminum with large amounts of cooling water in the cooling process of molten aluminum giant heat released into the cooling water to produce hot steam. Caster bearing is in a high temperature and water vapor environment, many bearing grease, grease add a relatively short time because of the high temperatures melt overflow is removed, maintenance difficulties, equipment surface hygiene also apply ease again. Further steel bearings in hot, humid environment is easy to rust corrosion, failure rate is very high, higher equipment maintenance costs, equipment operation subject to the following two problems often troubled.
   Fueling operation is difficult to achieve high-temperature continuous casting machine run pull ingots, ingot shift, then ingots, turned spindles and other devices are installed in the unit housing, housing demolition parking every grease, oil, grease gun pressure on people. And the whole point of oiling up to 30 multiple, long-term operation and maintenance can not achieve this kind of complicated oiling operation had to dilute oiler hand cream poured on the running external sleeve bearing, the lubricating oil is difficult to enter the bearing friction between large portion of the bearing friction in the state.
High ambient temperature, grease molybdenum disulfide grease suited to the current casting machine rolling bearing used in high temperature grease can be considered, and we know it is based on oil are petroleum products, plus a small amount of high temperature molybdenum disulfide additive, its temperature limit that is 1200C. According to the measured caster bearing operating temperature of up to 2000C, far beyond the grease becomes thinner and gradually evaporated, leaving a residue of carbon, molybdenum disulfide, dust mixed into a solid block solidified in rolling bearing holder, not only It loses its lubricating effect, but also impede the normal operation of the rolling bearing and wear out quickly, you have to shut down up to 2 weeks, remove the bearing grease cleaning renewal.
   First, wear condition
   Abnormal wear of bearing ingot casting equipment bearing the operation of the two problems are caused by more serious. In an enterprise pull starter mechanism, for example, bearing an average life of 2 months, wear serious virtues 5mm inner ring worn, so that the device can not continue to run. The reason is that the original design to the oil can not be achieved, bearing outside the shower had to run lean burn oil, pour a small amount can burn the bearing, the wear on the smaller, but more than 50% of the shaft and the sleeve are not lubricated, the friction in the soil generating a state strong adhesive wear. This wear and swim rapidly increasing gap between the shaft sleeve, the dust more accessible, creating a vicious cycle.
   Second, oil-free self-lubricating bearings selection
   In order to solve the high temperature mechanical equipment, low-speed, heavy-duty, large dust, water, shock and vibration have shower and lubrication problem, use oil-free self-lubricating bearings.
   1. Bearing structure
   Self-lubricating bearings are arranged in order to develop the metal friction surface bearing matrix size appropriate cavities, and embedded into a composite molybdenum disulfide and graphite self-lubricating block embedded in the metal sleeve, made of composite slider can 2800C work under high temperature. But because of its low mechanical strength, carrying capacity is weak, easily deformed, it will be able to insert in a hole in metal tank suppress this disadvantage, it forms part as support for metal, self-lubricating block for lubrication. This self-lubricating bearing lubrication mechanism in the shaft sleeve with oil dynamic friction process, the self-lubricating material part of the molecule is transferred to the metal surface of the shaft, filling the small, uneven surface and form a layer of relatively stable solid lubricating film , causing wear between body lubrication, shaft and sleeve to prevent adhesive wear. This is a reasonable combination of a combination of copper alloys and non-metallic materials by grinding their complementary advantages, especially for oil-free, high temperature, high load, low speed, anti-fouling, corrosion, strong radiation in the environment movement amplitude, and use the following solution in water or other infiltration impossible to add grease special working conditions.
   2. area
   Self-lubricating block area accounted for more than self-lubricating block accounted for much of the running speed of the surface area of the relevant bearing strength, low speed; large bearing strength, the area occupied by the metal should be larger. The grab ingot Trolley wheel bearing lubrication block occupies an area of about 25%, pull starter mechanism turn bearing lubrication to the full, not bearing strength, self-lubricating block occupies an area of about 65%.
 
   3. The liner material on technical requirements
   Bush should be used alloy of copper, bushings have a high hardness, are generally required heat treatment, the hardness is not less than HRC45.
   4. Since geometry and lubrication requirements mosaic block
   Self-lubricating block has a cylindrical shape and rectangular two kinds of self-lubricating cylindrical can according to the size of the area occupied, on the contrary may be rectangular. Whatever the shape of the inlay must be securely fastened to avoid falling in the operation.
   5. With the gap value of the bush and the shaft
 
   Bush and the shaft with the gap value of coefficient of linear expansion of steel are self-lubricating block 10 times. To meet the bearing temperature changes, the gap between the shaft and the bushing from the original metal parts moving with four (D4 / dc4) 0.032 ~ 0.15mm, increased to 0.45 ~ 0.5mm. Self-lubricating block friction liner side protruding metal 0.2 ~ 0.4mm. This will be fully lubricated bearings running at an initial break-in period, reducing the power consumption of power draw.
 
   6. Advantages of oil-free self-lubricating bearings
   a. No oil lubrication or less oily, apply to the oil or fuel is difficult to place, it can be used without maintenance or less maintenance.
   b. good wear resistance, low friction, long service life.
   c. have the right amount of elastoplastic, can stress distribution in a wide contact surface, increase the carrying capacity of the bearing.
   d. static and dynamic friction coefficients are similar, can eliminate crawling at low speed, thus ensuring the accuracy of machine operation.
   e. make the machinery to reduce vibration, reduce noise, prevent pollution and improve working conditions.
   f. In the operation process can form a lubricating film, played the role of protecting the shaft, no bite-axis phenomenon.
   g. For low hardness grinding axes, without conditioning the shaft can be used, thereby reducing the associated parts of the process difficult.
   h. thin-walled structure, light weight, can reduce the machine size.
   i. bushing made of brass can be used in corrosive media.
 
   Aluminum business through a practice, instead casting machine bearing oil-free self-lubricating bearings have been used continuously for 15 months, and is still running, gap between the shaft bushing is generally not more than 1mm, is also expected to re-use 12 months, significantly over the original life (2 months). Oil-free self-lubricating bearings can only get better used in the aluminum ingot casting machine, but can be adapted to oil-free, high temperature, high load, low speed, anti-fouling, corrosion, strong radiation in the environment movement amplitude, as well as in the water equipment or other solution infiltration under impossible to add grease special working conditions, these bearings consider worthy of our aluminum business.