Time：2020.06.05 Source：Roller Bearings Suppliers
All types of motor vehicles must meet increasingly stringent fuel consumption and environmental regulations. Therefore, driven by market demand, the size of turbocharged engines is continuously decreasing. In addition to diesel engines, gasoline engines in vehicles ranging from lightweight cars to heavy trucks are also equipped with turbochargers. We provide bearings for high-performance turbochargers, designed to meet the needs of small engines and improve engine speed and responsiveness.
Automotive turbocharger shaft bearing type
As a key moving part of the turbocharger, the structure of the bearing is related to the reliability and durability of the turbine. Turbocharger bearings are mainly divided into two categories, one is floating bearings (commonly known as Bosi bearings), and the other is ball bearings.
Most major automobile manufacturers now use floating bearings, which should be durable and affordable. The floating bearing is actually a ring that is sleeved on the shaft. There is a gap between the ring and the shaft and the ring and the bearing seat to form a double oil film. The ring floats between the shaft and the bearing seat. Generally, the inner layer gap is about 0.05mm, and the outer layer gap is about 0.1mm. The bearing wall thickness is about 3.0-4.5mm, and it is made of tin-lead bronze alloy.
The bearing surface is coated with a layer of lead-tin alloy or metal indium with a thickness of about 0.005-0.008mm. When the supercharger is working, the bearing rotates between the shaft and the bearing seat. Therefore, we can find the shortcomings of the floating bearing: the high-speed running resistance of the turbine shaft is high, the oil pressure and quality requirements are high, and the dynamic control of the turbine shaft is unstable.
Ball bearings are more visible on performance models. As the name implies, ball bearings are the installation of balls on the turbine shaft to replace the position of the oil in the floating bearings.
The advantage of the ball bearing is just the opposite of the floating bearing: the friction is smaller, the effect of turbo hysteresis is lower, and it is more beneficial to the pressing of the power limit; the dynamics of the turbine shaft can be effectively controlled; the oil pressure and quality can be slightly reduced , Indirectly increasing the life of the turbine.
The shortcomings are also obvious, that is, the life is not as long as the floating bearing, and the life limit is generally 70,000 to 80,000 kilometers, and the maintenance cost is expensive and the maintenance is difficult. However, because ball bearings are very tempting in terms of improving power, ball bearings are still the mainstream equipment on performance models.
Application and Research of Lubricating Grease for Floating Bearing and Ball Bearing in Turbocharger
I believe that when most people mention the structure of the turbocharger, the first reaction will be a turbine or a compressor, and they will think that the turbine and the compressor are the core of the manufacturers' technology. It seems that we have also missed a part that is "not very noticeable". Yes, it is the turbine shaft.
With a maximum speed of more than 150,000 rpm, it has sophisticated processing technology, superb mold processing standards, high temperature resistance and super wear-resistant materials. The entire selection process requires such a strict turbine shaft. The most core part of the compressor manufacturer. The turbine bearing that supports the turbine shaft is the protagonist of this article.
The bearing structure of the turbocharger is related to the reliability and durability of the turbine. Turbocharger bearings are mainly divided into two categories, one is floating bearings (commonly known as Bosi bearings), and the other is ball bearings.
Pseinu turbocharger floating bearing and ball bearing greases are made of fully synthetic mixed base oil, using special polymers as thickeners, and adding solid nano-lubricating materials, as well as various additives such as rust inhibitors and anti-wear properties. Refined .
This product can form a condensed reversible nano-lubricating layer on the lubricating surface, which can ensure the benign operation of lubricating parts for a long period. Conforms to US military standard MIL-G-21164. It can repair the lubricated surface microscopically, reduce vibration and reduce frictional noise. It can ensure that the lubricating parts can work effectively under super load and impact load; it has strong adsorption and permeability, and it is not afraid of sand washing; it has good colloid stability And the ability to resist acid gas medium; extremely strong physical and chemical stability, can extend the replenishment, fat cycle 5 times.
Widely used in high-temperature work, high-speed angular contact and deep groove ball bearings, such as: floating bearings and ball bearings in turbochargers, high-speed motor bearings, high-speed rail traction motors, high-speed railway axlebox bearings, NU series bearings for air-conditioning scroll compressors, Aviation, scientific research military equipment.