Bearing Assembly Requirements and Maintenance Methods

Precautions before bearing installation

1. Check the bearing for quality problems. Whether the rotation is flexible, carefully check the bearing parts for defects, such as indentation, burns, cracks, etc. It is strictly forbidden to install parts with quality problems.

2. Make sure the installation site is clean and prevent foreign matter from entering the bearing.

3. Make sure the bearings are clean, and do not install bearings that have not been cleaned.

4. Ensure the sealing quality. Carefully check whether the model specifications and sizes of the seals are appropriate, whether there are defects or quality problems, whether the related accessories are complete, and whether the cooperation is reasonable.

Precautions during bearing installation

1. Avoid hard mounting and impact. Be sure to gently install the bearing. The bearing and the seat hole have a small clearance. Normally, the end face should be tapped into the normal position. Surface wounds and even scrapped.

2. The bearing inner sleeve must be heated by induction and must not exceed 120°C. It is strictly forbidden to disassemble and assemble bearings by open flame.

3. When it is not easy to install, find out the reason, take reasonable measures after eliminating the problem, and timely repair when there are problems such as parts deformation, and if necessary, please revise the drawings.

4. Inject sufficient and clean grease in strict accordance with requirements.

5. When unqualified seals, glands and other parts are found in the installation, they must be strictly scrapped or repaired to ensure that the assembly quality meets the quality requirements.

Precautions for bearing disassembly

1. When the phenomenon of burning bearings is found, first of all, it is necessary to clarify the frame and bearing housing in time and make a record. In turn, check whether the lubricating oil is sufficient-whether it is water or oxide scale, whether the seal is damaged and whether the related accessories are used correctly-whether there is obvious friction relative to the rotating part-the external size of the bearing seat-the size of the seat hole, ellipse, taper 1. Make a record of whether the eccentricity and circle runout of the reference lining surface exceeds 0.05, etc., so as to further analyze the cause and take corresponding measures.

2. When removing the inner sleeve of the four-row cylindrical roller bearing, it must be heated with a bearing induction heater and must not exceed 120°C. When it is difficult to disassemble due to burning stick, it is less than a last resort, and it is strictly prohibited to burn and cut with fire.

3. In special cases, when the bearing inner sleeve must be cut with flame, it must be approved by the factory director, the reasons must be clarified and records must be made. If you decide to release it for reuse, you must go to the grinder to grind the roll neck. It is strictly forbidden to use only manual grinding wheel for simple grinding and then put it into use.

Preparation before bearing assembly

1. Preparation of measuring tools and tools

2. Inspection of parts

 Processing quality inspection of parts such as shafts, housings, end caps, bushings, seals, etc. The surface matched with the bearing should not have depressions, burrs, rust and solid particles.

3. Cleaning of parts

 Before installing the bearing, use diesel or kerosene to clean the shaft, housing and other parts, and wipe the matching surface with a clean cloth (not cotton yarn), and then apply a thin layer of oil to facilitate installation. All lubricating oil roads should be cleaned, inspected and ensured to be smooth.

4. Bearing cleaning

Bearings sealed with anti-rust oil can be cleaned with diesel or kerosene; bearings with dust caps or seal rings on both sides have been added with lubricants before leaving the factory, as long as the lubricants in the bearings are not damaged or deteriorated, when installing such bearings It is not necessary to clean; bearings coated with anti-rust and lubricating grease can also be cleaned during installation.

 The bearing should be filled with lubricant immediately after cleaning, and the bearing should be turned slowly when oiling, so that the grease enters between the rolling body and the raceway. The lubricating oil (grease) for bearings must be clean and free of dirt.

Overhaul of shaft and bearing seat

1. Overhaul of the shaft

First, use a dial indicator to check whether it is bent or deformed. If there is any deformation, turn, grind or straighten it.

 There should be no burrs or bumps on the mating surface of the shaft and the bearing, the perpendicularity of the shaft shoulder to the shaft, and the radius of the corner of the shaft shoulder should be measured.

2. Overhaul of bearing seat hole

Measure the roundness and cylindricity of the bearing housing hole, check the perpendicularity of the shaft shoulder of the bearing housing hole, etc.

Assembly of rolling bearings

1. Bearing installation with tight fit of inner ring and shaft, loose fit of outer ring and bearing seat

 The hammered end face of the assembly casing shall be processed into a spherical shape. Where there is no press or where the press cannot be used, the bearing can be installed with an assembly sleeve and a hammer.

2. The inner ring is loosely fitted with the shaft, and the outer ring is tightly fitted with the bearing seat.

Press the bearing into the bearing seat first, the outer diameter of the assembly sleeve should be slightly smaller than the diameter of the shell hole, and then install the shaft.

3. The inner ring and the shaft, the outer ring and the bearing seat are all closely fitting bearing installation

The end face of the assembly sleeve should be processed into a ring that can simultaneously compress the inner and outer ring end faces of the bearing to press the bearing into the shaft and the bearing seat hole. This method is suitable for the installation of self-aligning radial ball bearings.

4. Hot (cold) mounting method of bearings

Put the bearing or separable bearing ring into the oil and heat it evenly to 80~100℃ (should not exceed 100℃) before hot fitting, and then take it out and install it on the shaft quickly.

 When the rolling bearing is assembled by cold assembly method, it is generally not lower than -80℃ to avoid cold and brittle material.

5. Disassembly of rolling bearings

 Rolling bearings use hot assembly method, cold assembly method and hot unloading method, the advantage is that it will not destroy the interference, and the assembly and disassembly are both labor-saving and rapid.

Properties and applications of silicon carbide

Silicon nitride is an important structural ceramic material. It is a superhard material, which is lubricated and wear-resistant. It is an atomic crystal. Antioxidant at high temperature. Moreover, it can resist the cold and heat shock, heating in the air to more than 1000℃, cooling sharply and then heating sharply, it will not break. It is because of its excellent properties that silicon nitride ceramics are often used to manufacture mechanical components such as bearings, turbine blades, mechanical sealing rings and permanent moulds.

Silicon nitride is very strong, especially hot pressed silicon nitride, which is one of the hardest materials in the world. It is extremely resistant to high temperature, the strength has been able to maintain to 1200℃ high temperature without falling, heat will not melt into a melting body, until 1900℃ will decompose, and has amazing chemical corrosion resistance, can withstand almost all inorganic acid and caustic soda solution below 30%, also can withstand a lot of organic acid corrosion; It is also a kind of high performance electrical insulation material.

Silicon nitride – chemical formula Si3N4. White powdery crystals; The melting point was 1900℃, and the density was 3.44 g/cm (20℃). There are two variants: the leume type is a hexagonal dense accumulation structure; The type is like SPAR structure. Silicon nitride is gray with impurities or excess silicon.

Silicon nitride hardly interacts with water; Ammonium salt and silica were formed by slow hydrolysis in the solution of strong acid. Soluble in hydrofluoric acid, and dilute acid does not work. The solution of strong strong base can slowly corrode silicon nitride, and the molten strong base can quickly convert silicon nitride to silicate and ammonia. Silicon nitride can reduce the transition metal (see transition element) oxides, lead oxide, zinc oxide and tin dioxide at more than 600℃, and release nitrogen oxides and nitrogen dioxide. The following reactions occurred between silicon nitride and Ca3N2 nitride at 1285℃ :

Casin2 Ca3N2 + Si3N4 ─ – > 3

The relative molecular mass is 140.28. Gray, white, or off-white. It is a high-temperature insoluble compound with no melting point and strong resistance to high-temperature creep. The softening point of reaction sintering of silicon nitride without binder is above 1800℃. Hexagonal system. The crystal is hexahedral. The density of Si3N4 obtained by reaction sintering was 1.8~2.7g/cm3, and the density of Si3N4 obtained by hot pressing was 3.12~3.22g/cm3. Mohs hardness 9~9.5, vickers hardness is about 2200, micro hardness is 32630MPa. Melting point 1900℃ (under pressure). It is usually decomposed at about 1900℃ under normal pressure. The specific heat capacity is 0.71J/(g·K). The heat of formation is -751.57 kilojoules per mole. The thermal conductivity is (2-155) W/(m·K). The linear expansion coefficient is 2.8~3.2×10-6/℃(20~1000℃). Insoluble in water. Soluble in hydrofluoric acid. The temperature at which oxidation begins in air is 1300~1400℃. Specific volume resistance is 1.4×105 ·m at 20 ° c and 4×108 ·m at 500 ° c. The elastic modulus is 28420~46060MPa. The compressive strength is 490MPa (reaction-sintered). At 1285℃, it reacts with dicalcium disulfide to produce calcium disilicate. At 600℃, the transition metal is reduced and nitrogen oxides are released. The bending strength is 147MPa. It can be made by heating silicon powder in nitrogen or reacting silicon halide with ammonia. Resistivity in 10 ^ 15-10 ^ 16 Ω. Cm. It can be used as high temperature ceramic material.

Silicon nitride ceramic has the characteristics of high strength and high temperature resistance. Among the ceramic materials, its comprehensive mechanical properties are the best. It has the properties of heat shock resistance, oxidation resistance, wear resistance and corrosion resistance. In the mechanical industry, silicon nitride ceramics are used for ball bearings, rollers, ball seat rings, tools, new ceramic tools, pump plunger, spindle sealing materials, etc.

In the chemical industry, silicon nitride ceramics are used as wear – and corrosion-resistant components. Such as ball valve, pump body, combustion carburetor, filter, etc.

In the gold treatment industry, due to the high temperature resistance of silicon nitride ceramics, the friction coefficient is small, has the self-lubricity. For most metals, alloy solution stability, therefore, can be made of metal material processing tools, such as shifting rods, extrusion, wire casting mold, roller, transfer roller, heating fixture, thermocouple nesting, metal heat treatment supporting parts, crucible, aluminum liquid guide, aluminum lining.

Silicon nitride ceramic materials are also widely used in the electronics, military and nuclear industries.

Luoyang Tongrun Info Technology Co., Ltd. is committed to technology development, applications of nanotechnology and new material industries, with professional experience in the nano-technology research and development and the application of materials. As a leading nano-technology development and product applications manufacturer, the Luoyang Tongrun dominates the markets.

Tongrun technology provides solutions across the various processes and steps of laboratories and industries. Our professional working team provides the perfect solutions to help increase efficiency in various industries, create value, easy to deal with various challenges.

Currently our company has successfully developed serious of powder materials (including oxides, carbides, nitrides, single metal, etc.), high-purity target, functional ceramics and structural devices. OEM service is available. And our innovative, high-performance materials are widely used in all aspects of daily life, including but not limited to the automotive, electrical, electronics, information technology, petrochemical, oil, ceramics, paint, metallurgy, solar energy and catalysis.

Where Will The Major Oil Producers Wrestle With International Oil Prices?

Saudi Arabia, the world’s largest oil exporter, who recently announced a significant reduction in official oil prices and increased production. International oil prices on the 9th hit the most significant one-day drop since the 1991 Gulf War. Against the backdrop of weak global crude oil market demand, Saudi Arabia’s increase in output and price cuts will exacerbate the imbalance between supply and demand in the market. Where will the major oil producers fight to bring international oil prices?

It is understood that to balance market supply and demand. It stabilizes oil prices since the OPEC and non-OPEC oil-producing countries reached agreement on production reduction at the end of November 2016, they have maintained cooperation on production reduction.

Russia is the non-OPEC oil-producing country that has cut the most. But this time, Russia is unwilling to sacrifice market share to support oil prices. According to RIA Novosti News Agency, a spokesman for Rosneft, Russia’s largest oil producer, said that the output reduction agreement will not benefit Russia and will only allow the US shale oil to occupy more market share.

Bearings are an essential part of smelting petroleum equipment. Rotary disk bearings can be divided into four-point contact ball rotating disk bearings, crossed cylindrical (tapered) roller rotary disk bearings. Double-row four-point ball rotary disk bearings, double-row different diameter balls according to various structural types. Type rotary table bearings, ball-roller combinations, and three-row cylindrical roller combination rotary table bearings, etc .; the above types of bearings are divided into toothless, external gear, or Internal gear and other structures.

Turntable bearings can meet the needs of working hosts under various load conditions according to different structural points. Among them, the four-point contact ball turntable bearing has a higher dynamic load capacity. The crossed cylindrical roller turntable bearing has a higher static load capacity, and the three-row cylindrical roller combined turntable bearing leads to an increase in the bearing capacity to the height direction of the bearings. Separate raceways and roller sets take various loads, so under the same stress conditions, the diameter of its raceways is significantly reduced, which has the point of making the host more compact, and it is a high-capacity turntable bearing.

The World Bank announced that it would provide $ 12 billion to support members in responding to the novel crown pneumonia

The World Bank said in a statement that the funding was intended to help its members take effective action to respond to the outbreak and, where possible, mitigate the negative impact of the novel  crown pneumonia outbreak. The World Bank will help developing countries strengthen health systems, including better access to health services from the explosion, strengthen disease surveillance, strengthen public health interventions, and work with the private sector to reduce the impact of the outbreak on the economy.

According to the World Bank financing plan, the World Bank’s International Development Association will provide grants and low-interest loans to low-income countries. And the World Bank’s International Bank for Reconstruction and Development will give loans to middle-income countries. World Bank subsidiary IFC will provide its customers with the necessary support to continue operations and maintain employment. IFC will work with commercial bank customers to expand trade financing and liquidity loan quotas. It will also directly support its corporate customers, focusing on medical equipment and pharmaceutical sectors. At the same time, it will also support the bearing industry, which is the core of the industry. Maintain the supply chain and control risks.

World Bank President Malpass said in a statement that we are working to provide developing countries with “quick and flexible” support measures based on the needs of the novel  coronary pneumonia epidemic, including emergency financing, policy advice, and technical assistance…

At the same time, the IMF and the World Bank issued a joint statement.

The International Monetary Fund (IMF) President Georgieva and the World Bank President Malpas issued a joint statement. They are saying that the IMF and the World Bank are “ready” to help members deal with the challenges posed by the novel  coronavirus epidemic and specifically Focus on developing countries with weak health systems. The statement pointed out that strengthening national health surveillance and response systems are critical to controlling the spread of the epidemic. International cooperation is “critical” in addressing the health and economic impact of the novel  crown pneumonia epidemic.

In this epidemic, FAG Bearing will work hard to overcome the difficulties, step up the recovery of production, and reduce the negative impact that should be brought to the epidemic.

The Impact Of COVID-19 On The Upstream And Downstream Of The Automotive Industry Chain

The number of confirmed diagnoses of COVID-19 infection continues to increase, of which South Korea, Italy, Iran, and Japan increased the most. Till March 2, 2020, the number of confirmed diagnoses in South Korea reached 4812, and the number of Italians reached 2084. At the same time, COVID-19 has been reported to various industries. The development of the industry and national economies has multiple degrees of impact, especially on the upstream and downstream of the automotive industry chain.

The impact of the epidemic on the entire automotive industry is profound. In the short term, the effect on the automotive market is relatively significant, and the parts system is disrupted; in the long time, it may affect the layout of the industrial structure. “The specific impact is mainly distributed in the following areas: including reduced car purchase consumption, poor logistics, rising raw material costs, rising corporate production costs, etc., which will be transmitted to the entire automotive enterprise.” Bearings, as essential components, such as spherical roller thrust bearings the epidemic has also had a serious impact on the bearing industry in various countries.

In the long term, the emergence of new crown pneumonia may accelerate the optimization and adjustment of the industrial structure. Among them, the superior enterprises have relatively stable anti-risk capabilities and relatively fast recovery of operations. However, some companies are weak or have been eliminated by the market because of their weak innovation ability. Through this epidemic situation, our companies have also thought about how they will improve their competitiveness and anti-risk capabilities, and how to coordinate and coordinate among industries effectively.

It is believed that with the joint efforts of the whole world, the difficulties are only temporary, and the battle of COVID-19 will surely win.

How to Improve the Service Life of Needle Bearing

The needle roller bearing is a kind of bearing with a cylindrical roller. The roller is thin and long. It has a high load-bearing capacity when the radial space is limited. It is a bearing unit composed of centripetal needle roller bearing and thrust bearing. According to different occasions of use, the machining accuracy and surface quality should be combined with bearing rings and purposes. In typical applications, needle bearing can be divided into stamping outer ring needle bearing, reliable ferrule needle bearing, combined needle bearing, and thrust bearing. Therefore, it has a wide range of applications. And how to improve its service life is a critical issue.

To solve the problem, we must first understand the problem. First of all, what is the general cause of aging failure of needle roller bearing? Generally, there are four reasons and solutions: 1. The needle bearing is poorly lubricated and seriously lack of lubricating grease, which needs to be supplemented in time; 2. The bearing vibrates due to the failure of the machine iron core, which needs to be replaced with a new bearing; 3. The bearing fits too tightly, and the clearance is too small, which needs to be adjusted as soon as possible;4. The bearing material is tired. This is because of the fatigue of metal materials, the debris falling off the bearing raceway, and the ball surface drops into the grease, increasing by working noise. Therefore, we should consider the normal fatigue of bearing materials and replace the new needle bearing of the same model.

Also, to improve the service life of needle bearing, it is necessary to check and maintain it frequently. In this respect, many efforts are needed, such as no rain leakage in the warehouse, no direct sunlight in the bearing storage location, indoor air circulation. Still, no dust invasion, ventilation equipment, and temperature control equipment should be set in the warehouse, etc. After all, it’s our goal to ensure its performance.

What affects the charge of tin cabinets

While shopping for a cabinet of iron leather, quite a few people express very can’t understand why the rate of the workplace of a tin of the equal outdoors size can differ so much? In fact, this isn’t difficult to understand, similar to when you store online to peer many shops truly sell the identical style of garb; the charge will be a lot unique, this of course and product info, with substances, era, emblem benefits because of the cost isn’t enough to cause the rate difference. The same is true of the iron leather ark; iron leather ark also includes loads of types, as an instance, the cupboard of western-fashion ambry drawer, the cabinet of garage organizer, workplace drawer that takes the wheel to wait and so on.

The fee of an iron leather cabinet is determined by way of all styles of elements; usually, the trade of any individual element can affect the price alternate of the product. To iron leather-based ark, have no normal charge; for getting personnel, best master the factors that affect the price exchange of iron leather-based cabinet, if you want to buy better suitable for his or her personal iron leather cupboard. Because the producer that concentrates on generating iron leather ark, from oneself experience will proportion with you the component that affects iron leather ark has what, expect you can purchase the iron leather ark that fee, high-quality accords with oneself requirement.

1. The effect of fee on a price

We recognize, the cupboard of iron pores and skin, as its name indicates, is the cupboard that sheet iron makes. Its uncooked cloth is a steel plate. And the best of the steel plate now not simplest decided the fine of the iron leather cabinet; however, additionally decided the rate of the iron leather cupboard. The amount of the high-grade metal plate and the inferior metallic plate will now not range too much. Nevertheless, there is lots of distinction in fine, so it is not necessary to keep so a bit of money to buy inferior when shopping for a cupboard of iron leather-based.

2.The effect of exertions on charges

With the non-stop development of cloth society, the wages of the hard workforce also are growing. Hard work, due to the fact the value of its work has multiplied, is willing to paintings best if it earns extra than the charge of its paintings. Ironclad manufacturers, then again, are only ready to hire people if the marginal fee they are able to create is better than the wage they need to pay. Come so, the value of the labor force multiplied, which could cause the rate of the finished product of the cupboard of iron leather-based to upward push inevitably.

3.The effect of opposition between competitors on fees

This factor is highly difficult to understand as it isn’t as actual as of the effect of price and labor; the opposition between competitors is a notably nihilistic aspect. If it’s far healthy opposition, so the price of iron cabinet merchandise will fall; And if it’s miles a vicious opposition, it is straightforward to cause the ailment of marketplace costs.

4.The effect of the manufacturer’s income on the rate

Leather-based cupboard manufacturers are not charitable companies, but also want to make earnings, with the intention to feed personnel, to achieve the lengthy-time period improvement of the company. If the manufacturer’s advantage is too low, then the price will certainly rise to receive particularly massive profit space; If the manufacturer’s earnings margin itself is already vast, then that allows you to increase purchaser viscosity could be appropriate to reduce the price.

Both ways, the rate of any product is fraught with some uncertainty. For the purchaser, need to capture the possibility, if one wishes to buy an ark of iron leather-based, so be in after choosing excellent manufacturer trades as quickly as feasible, such capacity guarantees the stability of the fee.

The fee of the iron sheet submitting cupboard is high or low. What is more intuitive is the thickness of the metallic plate, this is, whether the reported cabinet uses the thick plate above 0.6mm. Absolute confidence, of a path, the dish approximately thick approximately sturdy, the better the cost.

Will tell; next, the procurement of excessive-grade sheet steel submitting cabinet still needs to see what form of cloth to apply, not handiest, at the identical time the place that details to every plank.

The iron sheet submitting cabinet might be break up, the board, hardware, clapboard and backboard, and other associated accessories are all separated to calculate the area and unit fee, the very last addition gets the specific actual place, subsequently following the value of the marketplace plate to calculate the price of the precise fabric item.

The price of a few regular true tin report cabinet is in seven hundred yuan above. Usually, brand and custom-made depending on the condition vary range rather. Metallic submitting shelves are numerous, the sorts of everyday tool cabinet, available on the market information, fission shelves, submitting cabinets, evidence shelves, and so forth., one of a kind process, cloth choice, etc. Will boost the charge of metallic filing shelves, consisting of growing the metallic cupboard more luxurious than regular one hundred fifty ~ two hundred yuan, colored metal cupboard extra pricey than typical a hundred yuan, can tear open outfit greater high-priced than no longer tear-unfastened tools of 50-a hundred yuan, in case you want to customize precise specs of the submitting cupboard, costs are generally higher. At present, the producer that has actual strength is in custom-made iron sheet furniture appreciate is to come back in keeping with this type of spread area valuation.

Compared with the traditional timber file cupboard, the tin file cupboard has big advantages in fire resistance, fastness, and environmental protection. The iron sheet filing cupboard is product of excellent cold-binding steel plate pressed, and its surface is covered with electro galvanization, warm-dip zinc, powder electrostatic spraying, after which sprayed with epoxy resin after phosphating remedy, accordingly forming a excessive hardness and durable chromaticity, in order to now not be everyday effect on the outside paint fall off or reason surface to sag. in order that the submitting cabinet is regularly new, coupled with the natural surroundings of the linear layout of the greater iron workplace regardless of a long time, is surely now not in the back of The instances. on the same time, the iron sheet cupboard non-poisonous tasteless, so that users use safer environmental protection. The tin record cupboard collection is generally mild, reasonably-priced, and easy mobile garage gadget.

INA needle bearing new product: miniaturization and low fric

 Keeping the SKF bearings is an essential condition for bearing procedure, the regular maintenance is for bearing lubrication. Under the facility of understanding the bearing lubrication method, it is additionally essential to recognize the maintenance of the bearing system. Currently, we discover how to do SKF birthing lubrication maintenance.

  The grease made use of in the bearings must have an antitrust impact, and the antirust agent is ideally insoluble in water. Grease needs to have superb adhesion to form an oil movie on the surface of the steel, also if the grease has plenty of water.

  1. Keep SKF Bearings Clean

  Bearings must be safeguarded from contamination by toxins and wetness; it must be correctly installed as well as lube. The design of the bearing arrangement, the problem of the oil seal, the type of lubes, and the lubrication cycle, likewise the unique upkeep, all play the same essential role.

  Keep the bearings tidy. Before inspecting SKF bearings, you ought to clean up the surface area of the bearings, and afterward, thoroughly examine the oil seals and also bordering components of the bearings. If there are signs, be sure to change them. Poor oil seals will trigger damages. The bearing cloud shape is uncommon, which causes the tools to stop.

  2. Check The SKF Bearing Lubricants

  Lubes are really vital not only for bearings but also for all SKF bearings. However, please note that it is not proper to add excessive oil to Japanese bearings, and afterward, it is time to replace the bearing lubricant. Oil-lubricated bearings must be replenished with fresh oil and also enabled the equipment to revolve at reduced speed for a number of mins after draining the old oil, preferably.

  Let the engine oil gathers as several residual impurities, and afterward, the oil is drained. For grease-lubricated bearings, the grease cleaner ought to be made use of to stop any cotton from entering contact with any part of the bearing. Due to these residual fibers may be wedged in between the rolling elements, and it will cause damages, particularly in birthing applications, this problem needs to be paid more interest to.

  3. Cover The Subjected Bearings

  Do not reveal the bearings to contaminants or wetness when examining the bearings. If the job is interrupted, the maker must be covered with a greased plastic sheet or comparable product. If the unshielded bearing is to be cleaned without dismantling and also assessment might be carried out, it needs to be cleaned with a brush used with a petroleum solvent and then wiped with a lint-free cloth or blown with compressed air.

  Use a small mirror along with a probe similar to that used by dental professionals to inspect the bearings’ track surface area, retainer, and beads. Do unclean bearings with closed caps or dust; you can just wipe the outer surface area. If the bearings are damaged, it requires to be changed. It is even more affordable to replace the bearings throughout the period of normal downtime upkeep than the loss of sudden downtime as a result of damage to the bearing.

Preparation Methods Of Boron Carbide Powder

Boron carbide has notable properties and is extensively used. Boron carbide  is second most effective to diamond and cubic boron nitride in hardness. It has  many advantages, along with excessive melting factor, low density, excessive  strength, broad neutron absorption go-phase, high-quality thermoelectric overall  performance, and proper mechanical stability. And we will use it in aerospace,  national defense, nuclear energy, and put on-resistant era.

At present, the carbothermal reduction is the number one method for the  commercial manufacturing of boron carbide. besides, the practices of boron  carbide manufacturing include self-propagating thermal reduction,  mechanochemical approach, direct synthesis, sol-gel method, and so forth.

1. Carbothermal discount

The carbothermal reduction method generally makes use of boric acid or boric  anhydride as raw material and carbon as a reducing agent to carry out  high-temperature reduction reaction in an electric powered arc furnace. At gift,  this technique is the primary technique of business manufacturing of boron  carbide, which has the benefits of easy reaction and occasional value.

Boric acid and carbon black had been used as uncooked materials and saved at  1700-1850 ℃ for h. The boron carbide powder with excessive purity  was calcined. The carbon content material turned into 20.7%, near the  theoretical cost. but, the disadvantages of this approach are: it desires to be  finished at a higher temperature, which consumes a variety of power; the boron  carbide production is simple to agglomerate, which desires to be overwhelmed;  the product is blended with unreacted carbon, which wishes to be eliminated by  means of subsequent remedy.

2. Self-propagating thermal reduction

The self-propagating thermal discount method uses carbon black (or coke) and  boric acid (or boric anhydride) as raw materials, energetic metal substance  (normally mg) as lowering agent or flux, and the warmth generated through  self-propagating combustion reaction of metallic substance are used to  synthesize boron carbide. The reaction equation is as follows: 6mg + C + 2b2o3 =  6mgo + B4C

This technique has the benefits of low initial reaction temperature (a  thousand-1200 ℃), energy saving, rapid response, and easy device. The  synthesized B4C powder has high purity and superb particle size (zero.1 – four.0  μ m) and commonly does not want to be beaten.

the use of Na2B4O7, Mg, and C as uncooked materials, Jiang et al. prepared  B4C powder with a particle size of zero.6 μ m by means of self-propagating  thermal discount. but the MgO produced through the reaction need to be removed  by means of additional manner, and it’s miles tough to do away with.

3. Mechanochemistry

The mechanochemical approach makes use of boron oxide powder, magnesium  powder and graphite powder as raw substances, using the rotation or vibration of  the ball mill to make the harder ball milling medium impact, grind and stir the  uncooked substances vigorously, and set off the chemical response at a  temperature slightly better than the room temperature to put together boron  carbide powder. The education temperature of this approach is low, so it’s miles  a promising guidance approach.

Deng et al. organized B4C powder with B2O3: C: Mg mass ratio of 10:1:eleven  through the mechanochemical technique. The particle size of the powder become  one hundred-200 nm. consistent with yogurt et al., the fine mass ratio of Mg: C  is nine:2 – 10:1. but, MgO, the spinoff of this technique, is challenging to be  obliterated, and it usually takes a long term for ball milling.

4. Direct synthesis

The direct boron carbide production approach is to prepare via thoroughly  blending the carbon powder and boron powder and reacting in a vacuum or inert  environment of 1700 – 2100 ℃. The purity of boron carbide prepared by direct  synthesis is high, and the B / C ratio in the reaction is simple to manipulate.  still, the practise method of boron carbide used for synthesis is fantastically  complicated and high fee. therefore, this method has a few barriers.

5. Sol-gel technique

Sol-gel technique (Sol-gel) refers back to the approach of solidifying  inorganic or metallic alkoxides via the answer, sol, and gel, after which  warmth-treated to gain solid compounds. the prevalence of this method is that  the aggregate of raw substances is more uniform, the reaction temperature is  low, the product is bulky, and the particle length of B4C powder is small.

Sinha et al. mixed the boric acid and citric acid under the conditions of  pH=2-three and eighty four-122. obvious and solid gold gel can be fashioned.  while heated to 700 tiers in a vacuum furnace, the porous smooth borate citric  acid precursor may be received. The precursor is saved below vacuum for a  thousand-1450 at 2h, and the B4C powder with a particle size of approximately  2.25 M can be obtained.

Luoyang Tongrun crew studied the impact of reaction time, temperature, and  extraordinary raw material ratio on the B4C within the boric acid citric acid  gel response device. whilst controlling the initial mass fee of boric acid and  citric acid to two.2:1, the content material of unfastened carbon within the  product become 2.38% when the response temperature become 1500 three.5H.  however, the manufacturing efficiency of this method is low, and it is not handy  to get massive-scale applications.

With the development of latest technological know-how and technology, boron  carbide performs a more and more critical position in enterprise and existence.  therefore, a suitable boron carbide manufacturing can be an essential  determinant of the improvement of boron carbide inside the future.