TIMKEN bearing use conditions for failure

Correctly grasp the TIMKEN bearings in the use of machinery parts and use condition and environment is the precondition of choosing suitable for rolling bearing. , need to get data and information on the following aspects: ( 1) Mechanism of function and structure, 2) The use of bearing parts ( 3) Bearing load ( Size, direction) ( 4) Rotation speed, 5) Vibration, shock, 6) Bearing temperature ( The surrounding temperature, temperature) ( 7) The surrounding atmosphere ( Corrosion, clean, lubricate) TIMKEN bearing configuration mode in general, the choice of shaft in two bearings in the radial and axial support, at this point, called the bearing on one side of the fixed side bearing, it bear radial and axial load, the fixed axis and the relative axial displacement between the bearing box. Call the other side free side, only bear radial load, axial relative movement can to solve due to temperature change the shaft of the telescopic part of the topic and the installation of bearing interval error. For a fixed side rolling bearing, it is necessary to choose available moving around the axial rolling surface, Such as cylindrical roller bearing) Or moving assembly plane ( If the centripetal ball bearings) The bearings. On the short shaft, the fixed side and free side little other cases, using only one-way KuangCheng fixed axial moving axis ( Such as the angular contact ball bearing) 。 Shaft material generally USES the carbon steel and alloy steel, generally USES the blank forging. Medium carbon steel with high quality for a lower and has higher comprehensive mechanical properties, widely used, of which the most widely used 45 # steel. In order to improve the axial force learning performance, should be quenched and tempered or normalizing treatment. Alloy steel with high mechanical properties, but its price is more expensive, many have special request for axial. , for example, large motor rotor shaft axle under the condition of high temperature, high speed and overloaded work, must have good mechanical properties at high temperatures, general often USES 40 cr, 35 simn, 42 simn alloy structural steel, etc. Is important to emphasize that the types of steel and heat treatment effect on the axial elastic modulus of the very small, if you would like to adopt alloy steel or by heat treatment to increase the stiffness of shaft, there is no practical results. In addition, the alloy steel sensitivity to the stress concentration is stronger, more attention should be paid to reduce the stress concentration from the structure and the surface roughness value. Since the 20th century 8. S, ductile iron casting axis progress soon. For example, the manufacture complex shape miscellaneous nodular cast iron crankshaft, has low cost, has good vibration and abrasion resistance, and low sensitivity to the stress concentration is more, but the disadvantage is that the impact toughness is low, the quality is not easy to control. TIMKEN shaft fracture, wear and failure is often characterized by excessive deformation, the main failure form is fatigue fracture. Journal due to wear and lose the original geometric shapes and sizes, into oval or conical, mild condition will make the parts fit between fine degrees lower, more serious when losing the original required function of parts in the shift. The dangers of excessive deformation is that axial loading to after, if produce too much bending deformation and torsion deformation, will affect the normal work of the shaft parts. Equipped with gear shaft bending deformation, for example, can make the gear mesh in partial load; Rolling bearing support shaft bending deformation can make the bearing inner and outer circle tilt, when more than permitted, will lead to lower bearing life quickly. Torsional deformation is too large, will affect the precision of the equipment and operation of the load distribution uniformity, and certain influence on the vibration of the shaft.