Method of aligning scroll compressor components

This invention relates to a method wherein the components adjacent the top and bottom of a scroll compressor are all aligned with regard to a common reference such that total alignment of the components can be more easily and accurately achieved. An improved method of aligning the bearing components within a scroll compressor includes the step of mounting the crankcase to be an interference fit within the center shell, and having a surface abutting a true upper surface of the shell. This ensures that the axis of the bearing in the crankcase is idealized and centered on the center axis of the center shell. At the same time, the lower bearing is mounted on the lower end cap, and is also cut to be concentric with a force fit outer surface of the end cap. This ensures the lower bearing is also centered on the inner periphery of the center shell. Once it is ensured the center shell is true, then it is also thus ensured the upper and lower bearings are aligned on a common axis. An improved lower bearing structure with a reverse taper is also disclosed. In some embodiments, the outer surface to be machined to be concentric with the inner surface is provided by a separate part which is welded to the lower end cap.