Pillow block bearings is a type of variations of deep groove ball bearings, the features is that the outside diameter surface of it outside track is in shape sphere, which can match concave sphere in bearing block so as to realize the function of self centering.

Although its basic performance should be similar to deep groove ball bearings, but since majority of such bearings are already used in crude machinery, and the installing and orientation are also not so accurate , the centering between axes and axes of race hole is very poor, or axes is too long together with bigger bending, moreover, the precision of bearing itself also not too high, someone even with crude structure, therefore, the actual performance of such bearings is not so good as same standard deep groove ball bearings. For examples: when pillow block bearings with jack bolt are used in through going shaft with poor rigidity and bigger amount of bending, the seal ring on two sides of bearings can prevent the entering of filth, meanwhile, before leaving factory, the bearings are already filled with certain amount of lubrication, it’s no need to clear up before installing, no need to add additional lubrication, while the jack bolt on the project end of inside track of bearings is tightened on the axes, the allowed axial load should not excess 20% of rating dynamic load.