Cylindrical roller bearings installation failure
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| Time：2016.09.12 News Sources：Shandong Xinkaite bearing Co.,Ltd. Views：
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Bearing installation should be preceded by cleaning with gasoline or kerosene to clean and dry before use, and to ensure good lubrication, bearings are generally lubricated with grease, oil lubrication can be. When using grease lubrication, should be used without impurities, oxidation, rust, extreme pressure grease superior performance. Grease filling is cylindrical roller bearings and bearing housing 30% -60% volume, not too much. With a sealing structure of the double row cylindrical roller bearing and water pump bearing grease has been populated, the user can be used directly, can no longer be cleaned.
Bearing installation, you must exert equal pressure on the circumference of the end face of the ferrule, the ferrule pressed into the top tool can not be a direct hit with Lang timken bearing end face so as not to damage the bearings. Small amount of interference in the case, may be pressed at room temperature with a sleeve bearing ring face, beating with a hammer sleeve, through the sleeve will be pressed into the ring evenly. If large quantities of installation, can be used hydraulic machine. Press-fitting, should ensure that the outer end face and the end face of the housing shoulder, the inner end surface of the shaft shoulder face pressed, does not allow the gap.
Bearing installation must be carried out in a dry, clean environment conditions. Should carefully check the mating surfaces of the shaft and housing, end shoulder, processing quality grooves and connecting surfaces before installation. All mating connector surface must be carefully cleaned and removing burrs, casting a net addition to the raw surface must be sand. When the amount of interference is large, can be heated in an oil bath or induction heating method to install the bearing, the heating temperature range is 80 ℃ -100 ℃, the maximum should not exceed 120 ℃. Meanwhile, the application of a nut or other suitable fastening method of the bearing, to prevent a gap between the widthwise shrinkage after leaving the cooling ring and the bearing shaft shoulder.
Finally, it should be adjusted bearing mounting clearance. The clearance values should be determined depending on the specific use conditions and the amount of interference fit size. When necessary, should be tested to determine. Double row cylindrical roller bearings and water pump bearing has been adjusted at the factory clearance, installation, do not have to adjust.
Bearing installation should be carried out after the rotation test, for the first rotating shaft or bearing box, without exception, then the power to conduct no-load, low speed, then gradually increase as the functioning of the rotation speed and load, and detects noise, vibration and temperature , abnormal operation should be stopped and checked. Before delivery after normal operation test.
Contact fatigue failure is one of various types of imported bearings The most common failure mode, failure is imported bearing surface by repeated cyclic contact stress effects produced. Contact fatigue spalling of the bearing surface of the part is from a fatigue crack initiation and propagation process to crack. The initial contact fatigue cracks are generated at the maximum orthogonal shear stress from the contact below the surface, and then extended to the surface pitting or small flake off like peeling, pitting former is known as pitting or spalling; the latter is called shallow spalling. If the initial cracks in the hardened layer and the core portion of the border area generated, resulting in early peeling of the hardened layer is called hardened layer peeling.
It is one of the most common kinds of bearing surface failure mode. The relative sliding between the bearing surface of the metal parts lead to friction losses constantly called sliding wear. Continuous wear parts will change in size and shape, the bearing with the gap increases, the deterioration of the working surface morphology, thereby losing precision rotation, so that the cylindrical roller bearing is not working properly. Sliding wear can be divided into abrasive wear, adhesive wear, corrosion and wear, fretting, etc., the most common abrasive wear and adhesive wear.
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