The Perfect Oilless SGO
There are pressing fit and cooling fit for inserting the bearing into the housing.
Nitrogen and dry ice are used for cooling fit. Compared to pressing fit, it can acheive more accurate installation. Shrinkage fit can deteriorate the bearing function.
In general, mandrel and press machine are used for pressing the oil-less bearing into the housing. As indicated on the figure, oil-less bearing is pressed into the housinghe with jig (fixing device) by a small press. In case of pressing large product, chamfering should be made on the bearing external diameter and housing internal diameter first before using the oil.
Heat expansion coefficient
#500SP : a = 2.2 X 10-5℃
#500B : a = 1.8 X 10-5℃
#500F : a = 1.2 X 10-5℃
* Refer to it for below diameter 500 mm
Ex) #500SP I.D 100 x O.D 130 x 100L
Room temperature 20℃, Cooling temperature -70℃
ΔD = 130 x 2.2 x 0.00001 X (20 - (-70)) = 0.2574