General FAG Bearings steel is mainly carbon chromium bearing steel, ie about 1% carbon content, adding about 1.5% chromium, and contains small amounts of manganese, silicon element eutectoid steel. Heat treatment can improve the performance of chromium, improve the hardenability, tissue uniformity, tempering stability, higher purity, non-metallic inclusions in steel less. Bearing steel oxides, silicates and other harmful inclusions leading to premature bearing fatigue spalling, a significant reduction of the main bearing life. Especially damaging brittle inclusions, because in the process from the metal substrate is easy to come off, seriously affecting the bearing parts after finishing surface quality. Therefore, in order to improve bearing life and reliability must be reduced bearing inclusions in steel content.
It's the same dangers and brittle inclusions. Carbide reduce the impact toughness, and make inhomogeneity, easily deformed during quenching and cracking. Carbide strip annealing and quenching and tempering influence organizations and contact fatigue strength. Low, high-powered organization on the merits of performance and service life of rolling bearings have a great impact, so in FAG bearing material standards for low, high-powered organizations have strict requirements. In bearing steel, if there is a serious carbide distribution is uneven, then the heat treatment process can easily result in non-uniform microstructure and hardness of steel tissue heterogeneity on contact fatigue strength has a greater impact. In addition, severe unevenness carbide also easy to make the bearing parts in the quenching cracks, unevenness carbide bearing life can lead to decreased Accordingly, in the standard bearing materials of different specifications of steel have a clear special requirements.
In standard bearing material surface decarburization of the steel has strict rules, if the surface decarburization beyond the standard specified range, and before the heat treatment during processing nor removed in its entirety, then the heat treatment and quenching process for the prone to quench cracking, resulting in scrapped parts.
In lubricated bearings, oil coated the better you lubricate bearings, oil coated the better, this is a common misconception. FAG bearings and bearing interior excess grease will cause excessive oil mixing, resulting in extremely high temperatures. For separate bearings are indifferent clearance; Finally, the bearing clearance work after installation, pre-installation of the original than the clearance is small, because the bearings to withstand a certain load rotation, as well as coordination and load bearing elastic deformation arising volume.
How to choose the grease lubrication of the bearing operation and life has a very important influence. Here introduces you to choose the general principles of grease. Grease from the base oil, thickener and additives made of different types and different brands of the same type of grease performance varied widely, allowing different rotation limit, the choice is important to note. The performance of the grease determined by the base oil. Other low viscosity base oil for low temperature, high speed; high viscosity suitable for high temperature, high load. Between the lubrication performance thickeners, grease thickeners water determines the water resistance. In principle, you can not mix greases of different brands, and even the same kind of grease thickener, also due to the different additives adversely affect each other.
Place on the mounting surface and installation requirements? Yes. If there is iron bearing, burrs, dust and other foreign matter entering the bearing will generate noise and vibration during operation, and may even damage the raceway and rolling elements. So, before installing the bearing, you must ensure that the mounting surface and installation environment clean.
During rotation of the bearing cage free vibration and its rings and rolling bodies collide or will be issued this noise. It can occur in both types of bearings, but its sound pressure level is not too high and low frequencies. Its characteristics are: a. Stamping cage and plastic cage can produce. b. Whether thin oil or grease lubrication will appear. c. outer withstand the moment when the most prone. d. radial clearance is large prone.
Raceway sound is due to rotation of the bearing rolling elements and the raceway scroll inspire a kind of smooth and continuous noise, only when its sound pressure level or tone when aroused great attention. In fact, inspired raceway sound acoustic energy is limited, as in normal circumstances, high-quality sound of 6203 bearing raceway 25 ~ 27dB. Its characteristics are: a. Bearing radial clearance is easy to produce large. b. usually appear in grease lubrication, oil lubrication is relatively rare. c. with the bearing size increases and decreases, and often occur within a certain speed range. d. winter often occur. e. Its appearance is irregular and unpredictable, and with the filling fat content, performance and installation operating conditions. This noise can be reduced radial bearing clearance and the use of shallow outer raceway structure to prevent it.
But the effect of centrifugal force may be in contact with the outer end, at low speed, when the centrifugal force is less than the weight of the rolling element rolling experience with the inner raceway fall or collision and excitation cage FAG bearing natural vibration and noise, and has the following characteristics: a. grease lubrication is easy to produce, easy to produce oil lubrication. When more likely to have low-grade grease. b. winter often occur. c. role for only radial loads and larger radial clearance is also easy to produce.


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