Rolling related considerations
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| Time：2016.09.06 News Sources：Shandong Xinkaite bearing Co.,Ltd. Views：
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Technical standards and considerations of rolling bearings
1, with the use of bearing and shaft hole basis, bearing and housing with the use of basic shaft system. Bearing values specified dimensional tolerance and rotation precision of the press GB307-84.
2, the journal and the bearing housing bore and bearing with the provisions in accordance with GB1031-83, the journal roughness Ra value of less than 1.6μm, the bearings inside the hole roughness Ra value of less than 2.5μm.
3, with GCr15 steel bearing rings and ZGCr15 midnight and roll, its rings and roller hardness value should be 61 ~ 65HRC; ZGCr15SiMn time by GCr15SiMn and steel, its hardness value should be 60 ~ 64HRC. Hardness inspection method and the same part of the hardness uniformity according to the provisions of JB1255.
4, check the bearing radial clearance and axial clearance shall comply with the provisions of GB4604-84.
5, the bearing inner and outer ring raceway should be no falling off, badly worn, both inside and outside the ring without cracks; the ball should be no wear, no serious deformation cage, no abnormal noise and vibration during rotation should be stopped gradually stop.
6, C-level tolerances for tapered roller bearings, the roller and ring raceway contact with precision, under the action of a certain load, coloring check, contact marks should be continuous, the contact length of not less than picture-line roller 80.
Bearing life with the manufacture, assembly, use all closely related, must make every link in order to make the bearing in the best operating condition, thus extending bearing life.
1, shaft and bearing housing tolerances choice and control: bearings pressed into the bearing block should be flexible rotation no sense. If significant rotation is not flexible, it means that the shaft size is too large, cut to tolerances. The bearing pressed into the shaft turned by hand after the obvious "imperfections" in a sense, it may be too much tolerance of the shaft or shaft roundness is not good. So when good control shaft and bearing housing tolerances should control the roundness, many domestic manufacturers only the tolerance control, no control of roundness.
2, the bearing assembly methods: Because bearings are precision products, such as improper assembly is likely to cause damage to the bearing channel, leading to bearing damage. Bearing in the assembly should have a dedicated mold and can not beat, when pressed into the shaft force only a small circle, the circle can only force when pressing circle. Assembly requires the use of pneumatic or hydraulic pressure, when the press-fit to the outer upper and lower mold in a horizontal state, if inclined bearing channel will lead to damage due to power, leaving the bearings guide ring.
3, fitted to prevent foreign bodies: bearing mounted to the rotor dynamic balance when it is easy to iron produced when balancing into the interior of the bearing, so do the balancing is best fitted before the bearing. Some manufacturers in order to facilitate assembly, the assembly in the bearing chamber coated with some oil or grease lubrication effect, but the operator is often difficult to control the amount, if oil or grease in the bearing interior accumulates more in the bearing rotates very easy access to the interior along the shaft bearing. Bearing chamber is preferably not coated with oil or grease, such as non-coated non-bearings shall have to control indoor accumulates.
4, paint rust prevention: After paint rust is characterized by multiple sealed-type motor, the motor assembly, sound good, but put in the warehouse for some time, the motor becomes very abnormal sound, remove the bearing severe rusting. Many manufacturers will be considered to be bearing problem, through our continuous propaganda, now the motor plant has been realized mainly insulating paint problems. The main problem is because the insulating paint out of the volatile acidic substance at a certain temperature, humidity, corrosive substances are formed, resulting in damage to the bearing channel bearing corrosion. This problem can only be a good choice of insulating paint, and after a period of time after drying ventilation assembly.
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