We can provide free samples . Please contact Email for any inquiries

According to the forming mechanism of imported bearing working surface of the grinding affected layer, the main factors affecting the grinding affected layer is heat and grinding forces and grinding effect. Below we will analyze about bearing failure.
1.KOYO bearing grinding heat
In the KOYO bearings grinding, grinding wheel and workpiece contact zone, consume large amounts of energy, grinding heat large, causing local instantaneous high temperature of the grinding zone. Using the instantaneous temperature linear moving heat source theory formula of heat transfer calculation, or the application of infrared ray method and thermocouple measured under the experimental conditions, can be found in the 0.1 ~ 0.001ms instantaneous temperature inside the grinding zone can be up to 1000 ~ 1500 ℃. The instantaneous high temperature this, enough to produce high temperature oxidation surface layer surface depth, the amorphous structure, high temperature tempering, two times quenching, or even burn crack a variety of changes.

(1) surface oxidation layer
Oxygen steel surface under the action of high temperature instantaneous and in the air, ascending into very thin (20 ~ 30nm) of the iron oxide layer. Worthy of note is the result of the test of total thickness of oxide layer thickness and surface grinding affected layer is a corresponding relationship. This shows that the thickness of the oxide layer and the grinding process is directly related to, is an important symbol of grinding quality.
(2) amorphous layer
The instantaneous high temperature of the grinding zone so that the workpiece surface reach the molten state, metal molecular molten flow is evenly coated on the surface, and the base metal to speed cooling fast, forming a thin layer of amorphous layer. It has high hardness and toughness, but it was only about 10nm, it is easy to be removed in the precision grinding.
(3) high temperature tempering layer
The instantaneous high temperature of the grinding zone can make certain the depth of surface (10 ~ 100nm) is heated above the tempering temperature of workpiece. At the austenitizing temperature did not reach the case, with the heating temperature increasing, the surface by changing layer will produce corresponding with the heating temperature and tempering or high temperature tempering microstructure, hardness decreased. The heating temperature is higher, the hardness decreases more.
(4) two layers of hardened layer
When the instantaneous temperature of the grinding zone the workpiece surface layer is heated to the austenitizing temperature (Ac1) above, the layer of austenitic organization in the subsequent cooling process, again by quenching into martensite. There are generally two times quenching the workpiece burn, under the second quenching layer must be high temperature tempering layer of very low hardness.
(5) the grinding crack
Two times quenching burn will make the surface layer stress changes. Two quenched region in the state of compression, the following high temperature tempering zone material has the largest tensile stress, it is most likely to occur where the core crack. Most likely crack propagation along the original austenite grain boundary. Serious burns may lead to crack the whole grinding surface (a crack) cause the scrap.
The size and quality of a KOYO bearing rolling sound, the sound of the bearing in operation rolling sound check, bearing even a slight separation of the injury, also issued abnormal sound and irregular sound, with sound measuring device can distinguish.
Two, the bearing vibration is very sensitive to the bearing damage, such as peeling, indentation, rust, crack, wear will be reflected, in the measurement of bearing vibration so, through the use of special bearing vibration measuring device (frequency analyzer etc) can measure the size of the vibration, the frequency analysis can not be inferred from abnormal situation the. The measured values, and different bearing conditions of use or the sensor installation location, therefore require prior to each machine measurement comparison criteria.
Three, the temperature of the bearing, general bearing outside of room temperature can be speculated that, if the uses of oil hole can directly measure the bearing outer ring temperature, is more appropriate. Usually, the temperature of the bearing with running slowly rising, reach a steady state after 1-2 hours. The normal temperature of the bearing is due to the heat capacity, the machine heat dissipating capacity, speed and load and different. If the lubrication, install appropriate, bearing temperature will rise rapidly, there will be abnormal high temperature, then we must stop, take the necessary preventive measures. The use of thermal exchanger can always monitor the bearing temperature, and when the temperature exceeds the specified value alarm households or stop to prevent burning shaft accident.
Four, lubrication has important influence on the fatigue life of rolling bearings and friction, wear, Wen Sheng, vibration, no normal lubrication, the bearings will not work. Analysis of the causes of KOYO bearing damage that, around 40% of bearing damage related to poor lubrication.