2014年4月8日星期二

The basic set of clearance values ​​for general working conditions, should be preferred

bearing and shaft and housing bore with the tightness will lead to changes in the bearing clearance values. After the general bearing clearance will reduce the value of the installation ;
during operation of the special bearing body due to different thermal conditions of the shaft and the housing , between the inner ring and the outer ring to generate a temperature difference , which will lead to reduced clearance value ;
Due to the shaft and housing material due to different coefficients of expansion , will lead to reduced or increased clearance values.

Radial bearings usually choose the most suitable operating clearance value is the fundamental group bearing clearance clearance values ​​as specified in the standard . The basic set of clearance values ​​for general working conditions, should be preferred. When the radial bearings working under special conditions not using the basic set of clearance, clearance optional secondary group values ​​. Groups such as 3,4,5 clearance tapered roller bearing values ​​deep groove ball bearings for bearing and shaft and housing bore adopt tighter than normal interference fit with the bearing inner and outer rings or large temperature difference between the work of the mechanical components . Inclination of the axis of the center and the shell hole in the center line of the larger , and axial load in order to increase its ability to improve the bearing speed limit , and lower friction bearings and other working conditions , the tour group will also adopt 3,4,5 gap value. Precision requirements or restrictions for axial rotation axis swimming , the general group 2 clearance values ​​( smaller clearance value ) of the bearing , if necessary, to give some pre- load " preload " to improve the rigidity of the shaft.

2014年4月1日星期二

WhenTapered roller bearings operation if there rhythmic percussion or crash

When bearing operation if there rhythmic percussion or crash , probably due to the cylindrical roller bearing raceway spalling, indentation , or other parts caused by improper installation ;  2)  bearings have found "Goo busy , goo busy "sound, may be due to the bearing Mifengbuyan , oil is not clean , bearing clearance caused by too much ;  3) found bearing the" enjoin squeak , squeak enjoin " screaming sound , may be due to dry lubricant or lack of lubricant caused ;  4) If it is found tapered roller bearings  the " Falling " sound , may be cylindrical roller bearings are not clean, interior mixed with debris , sand , dust and other debris caused by ;  5) excessive heat expansion of the bearing inner ring , bearings and seals and related parts friction ;  6) when installing bearings, thrust ball bearing  or other parts due to beating , causing bearing deformation ;  7) bearings the adapter sleeve too tight or loose ;  8) of the bearing housing oversize ( including the use of larger ) , causing  bearing outer ring rotates in the bearing seat  and so on, are likely to make bearings noise and unusual sound. Cylindrical roller bearings causes vibration , basically causes abnormal bearing noise and sound the same , there is a strong correlation between the two.