Scroll-type apparatus having a pivoting main journal bearing

摘要

A scroll-type apparatus having a main journal bearing which journals the drive shaft of the apparatus and is capable of pivoting by small angles with two degrees of freedom. The main journal bearing comprises three or more arcuate pads whose inner surfaces journal the drive shaft and which are pivotably supported by a stationary main bearing housing. In a preferred embodiment, each of the pads has a spherical protrusion and two rotation-preventing pins secured to its back surface. The protrusions contact the inner surface of the main bearing housing and pivotably support the pads, while the rotation-preventing pins are inserted into grooves formed on the inner surface of the main bearing housing. When a load is applied to the drive shaft causing it to tilt, the pads of the main journal bearing can tilt along with the drive shaft by pivoting about the points of contact between the spherical protrusions and the inner surface of the main bearing housing, thereby preventing edge loading of the main journal bearing.