Scroll type device including compressor and expander functions in a single scroll plate pair

A scroll type device for operating on a fluid introduced there into, comprising, as an operable unit,

• a housing;
• two scroll plates, each having centers, outer limits, and facing sides with spiral projections thereon;
• said scroll plates installed within said housing with said facing sides facing one another and with said spiral projections thereon interleaved to form a scroll plate pair;
• said scroll plates being operably movable relative to one another in an eccentric orbit;
• each of said spiral projections including first and second spiral portions, with said first and second spiral portions forming an inner involute spiral that spirals outwardly from the center in one spiral direction to an intermediate spiral point located intermediately between said center and the outer limit of said scroll plate, and a second spiral portion forming an outer involute spiral that spirals outwardly from said intermediate spiral point in the counter direction from that of said inner involute spiral to an outer spiral point near said outer limit of said scroll plate, the counter direction of the second spiral portion relative to the first spiral portion for effecting compression of any fluid in one of the spiral portions and for effecting expansion of any fluid in the other one of said spiral portions;
• said scroll plates and said first and second spiral portions thereon forming a scroll set that includes inner and outer scroll set portions;
• said inner scroll set portion having an inlet port associated therewith near the centers of said scroll plates and an outlet port associated therewith near said intermediate spiral points of said scroll plates;
• said outer scroll set portion having an inlet port associated therewith near said outer spiral points of said scroll plates and an outlet port associated therewith near said intermediate spiral points of said scroll plates;
• said outer scroll set portions operable to function as a scroll compressor during normal eccentric orbital movement of said scroll plates in a given movement direction, and the other said inner scroll set portion operable to function as a scroll expander during said normal eccentric orbital movement of said scroll plates in said same given movement direction;
• one of said scroll plates is fixed and the other scroll plate is movable;
• a plurality of rotatable idler shafts for controlling the movement of said movable scroll plate relative to said fixed scroll plate, and there being a spacing between said scroll plates;
• a thrust bearing for controlling, in cooperation with said idler shafts, the movement of said scroll plates;
• each of said idler shafts includes first and second shaft portions having offset axes, said first shaft portion extending through one of said scroll plates and said second shaft portion extending through the other of said scroll plates, whereby eccentric orbital movement of said scroll plates is effected by rotation of said idler shafts;
• a set of mounting bearings for each of said idler shafts and wherein said idler shaft is mounted in said set of mounting bearings and extends through said scroll plates;
• said plurality of idler shafts includes three idler shafts spaced generally equilaterally about the center of said scroll set;
• said inner scroll set portion will operate for expansion and said outer scroll of said portion will operate for compression;
• the inlet provided at the outer spiral point is a compressor inlet for fluid, the outlet provided at the intermediate spiral point is a compressor discharge and expander discharge for fluid, and the inlet provided at the center is an expander inlet for fluid;
• and
• whereby, as the scroll type device operates in said given movement of direction with said scroll plates moving relative to one another in a given eccentric orbit, one of said inner and outer scroll set portions operates as a scroll expander to expand fluid provided thereto at said inlet port for said scroll set portion and to discharge the expanded fluid at said intermediate outlet port for said scroll set portion, and the other of said inner and outer scroll set portions operates as a scroll compressor to compress fluid provided thereto at said inlet port for said scroll set portion, and to discharge the compressed fluid at the intermediate outlet port for said scroll set portion depending upon the delivery of fluid to either the compression or expansion inlet ports.