Originally Posted by
handlewanker
Hi Philbur, not quite sure what you mean by top bearing "pivoting" round the bottom bearing, the top bearing is a radial load carying ball race (it could also be a roller bearing, but needs sealing) and as such only has to resist side loads only like the pull of a belt, and as a ball radial bearing you would be hard pressed to find any side to side movement in the top bearing, but to allow for thermal expansion the top bearing is allowed to move up or down on the spindle or in the housing, approx a few thou is sufficient.....the bearing being a sliding fit......this also allows the bearing to be lubricated and sealed for life, as it's very difficult to make a seperate lube system and seals in this area.
Ian.