Method For Improving Compressor Housing Crack

Compressor housing often leads to parts crack or fracture phenomenon because of the defects of casting and machining, the internal stress and overload operation. Once the crack happen, you must take reasonable methods. The common repair method is using welding. But some parts material may be cast iron, aluminum alloy or titanium alloy, these are all difficult to do the welding processing.

Some dangerous occasions which are easy to explosion had better not adopt welding repair method. The new cold welding technology can avoid thermal stress and deformation. At the same time, the material usually own good adhesion and comprehensive performance of compressive strength, and corrosion resistance. So that this new technology can satisfy the requirement for compressor housing in the maximum. It can ensure effective operation at the inputs with lowest cost.

Compressor is mainly based on welding and brush plating spray. But both of them exist some defects. Thermal stress generated by the high temperature of repair welding can not be eliminated completely. On the contrary, it is easy to cause material damage and even lead to bend and break. Brush plating is limited by coating thickness, it is easy to peeling.

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Choose A Suitable Bearing

Turbocharger is one of the important technology in the future automotive development. Compared to the naturally aspirated engine which with equal power, the turbocharger always own smaller displacement and lower oil consumption. It has a positive significance on energy saving and emission reduction. When the energy worked, there is a part of the oil supply of turbocharger rotor bearing lubrication and it also could used for cooling.

The running energy stopped suddenly and the oil pressure decreased to zero. The high temperature of turbocharger parts pass to the middle and the heat of bearing shell can not be took away quickly. At the same time, turbocharger rotor is still rotating in high speed with the effect of inertia. So it is easy to make the oil too hot and even damage the bearing if the energy stopped suddenly in heat state.

Turbocharger is composed by fixed nozzle ring, rotating impeller and turbine shell. Some small turbochargers are without nozzle ring because it could reduce the volume and weight, and even make its structure simple. This is called non turbine shell. Turbine impeller and the compressor working wheels shares one rotating shaft, the rotor is just composed by these three parts. With the high speed of the rotor, we muse check its dynamic balance and choose a suitable bearing type to ensure the turbocharger work successfully.

Solve Common Problems In Bearing House

Wear is the most common problem to bearing house. The traditional method to solve this problem is processing by welding machine to repair. Surfacing will make parts surface reach to high temperature and even make the part deformation or cracks. Nowadays we adopt polymer composite materials to repair it on site. There is not any limited to repair the thickness. Repairing in site can save a lot of downtime to manufacture and even create huge production.

The repairing process is very simple. At first, you should do some surface treatment. It means that you should remove grease and moisture from bearing house surface. Then reconcile repairing materials. Secondly, painting the material on the repair parts of the bearing house evenly and filled it strongly. After the material has been cured, you can heat its surface properly and accelerated material curing.

Generally speaking, bearing house wear can be repaired about three hours or even more, but it must be less than six hours. This operation usually easy to learn and don’t need any special equipment and professional training. While on site repairing has reduce the equipment repairing time and transportation cost.

Changing Judgment For Turbocharger Spare Parts

Whether the turbocharger spar parts need change or not is rely on many factors, such as ablation, wear and deformation. In daily life, you had better check turbocharger spar parts carefully.

Sealing ring will produce wear if the turbocharger working with dry friction intermittently. After disassemble, the sealing ring is difficult to recovery and its sealing will be decreased. At this time, you must replace it with a new one. The inner and outer ring of floating bearing are all in the oil film. At the same time, there is little wear. If you find the oil become dirty, oil film scratched or the bearing deformation, you should change floating bearing as soon as possible.

Generally speaking, thrust bearing plate will be without any wear if the oil is enough. But it is easy to plug oil hole if the oil become dirty. Then you may replace it according to the real situation. After the turbine shaft working for a period of time, the shaft surface will be in high temperature and its color will be changed too. As long as there is no obvious scratches and grooves of the shaft neck, you can continue to use. Inner hole wall of floating bearing will not wear due to enough oil supply. You could not change new one if there is no obvious scratch.

Take Good Maintain To Thrust Bearings

Generally speaking, thrust bearing is used on the parts which under axial load side and in high speed, such as crane hook, vertical pump, Hoisting jack and speed reducer. Bearing ring, seat and roller are separate and could assembly and disassembly respectively.

Pump which used just now usually should change the grease after working 100 hours. Then you can change it about 500 hours once. Thrust ball bearing which use grease had better change the grease 1500 hours once, filling oil quantity should be moderate. The thrust ball bearing will be heating because without appropriate amount of grease. In general, the gas volume had better in half or even more.

Container for lubricating oil and lubricating grease should be clean and also in good daily sealing. Dust, debris and other sundries can not exist. So that it will not damage trust ball bearing. Motor thrust ball bearings often use sodium base grease. This nature of the lubricating grease can be resistant to high temperature. But it can dissolve in water. So don’t this lubricating grease in trust ball bearing.

Alloy Material Requirements For Journal Bearings

There are some requirements for journal bearings. Firstly, journal bearings should own enough fatigue resistance. The alloy material will have tiny cracks under alternating load if it has exceed fatigue strength, and even depth development until form alloy layer and  peeling. Secondly, journal bearings need enough wear performance. It includes seizure resistance, compliance, embedded possession and other performance. So journal bearings could be adapt to the negative effects, such as frequent cold starts, short oil, dirty oil or poor performance. Thirdly, Journal bearings had better own good corrosion resistance. Even the journal bearings works in the bad oil, its performance still be stable. Certainly, journal bearings must have enough bond strength in order to ensure that it will not drag shell under dual role.

At present, there are two methods to analysis and calculation nonlinear journal bearings. One adopt numerical methods to solve Reynolds equation directly. Another is analytic method. The former one has high precision, but the calculation speed is slow. The latter one is more easier.

Journal bearing is widely used in precision rotating machinery. Do nonlinear analysis to the radial journal bearing rotor system, and explore the the instability mechanism. It can not only offer theoretical basis to rotating machinery optimization design, mechanical control, fault monitoring and diagnosis, but also has important realistic significance.

Nozzle Ring In Turbocharger

Recent years, he automobile industry has been booming in China and it also has been new pillar to national economy. China has become largest auto market in the world in the year of 2010. With the greatly improved of car ownership, the difficult problem of environmental pollution brought by cars has become placed in front of people.

Some countries have put forward the automobile exhaust emission standards. Certainly China is not exception. The invention and application of turbocharger technology are not only decrease fuel consumption and improve the power of the engine, but also reduce the harmful gas in automobile exhaust components. So Countries of the world, especially the developed countries put a lot of manpower in turbocharger technology and manufacturing. Variable nozzle turbocharger technology is a new technology and has been widely used. It has broad future development.

Nozzle ring vane is the key component for variable nozzle turbocharger. At precent, there is nothing special processing equipment since this technique has just appeared. Now the main process of nozzle blade machining is casting or forging blank. Then machining and optical finishing. Generally speaking, people adopt the method of grinding wheel by hand in China. This is not efficient. However there are many technical personnels studying on the new method in order to improving efficiency.