Compressor having capacity modulation assembly

A compressor comprising:

• a shell assembly defining a suction-pressure region and a discharge-pressure region, said shell assembly including a partition separating said suction-pressure region from said discharge-pressure region;
• a first scroll member disposed within said shell assembly and including a first end plate having a discharge passage, a modulation port, a biasing passage, and a first spiral wrap extending from said first end plate;
• a second scroll member disposed within said shell assembly and including a second end plate having a second spiral wrap extending therefrom, said first and second spiral wraps meshingly engaged and forming a series of pockets during orbital displacement of said second scroll member relative to said first scroll member, said modulation port in communication with a first one of said pockets, said biasing passage in communication with a second one of said pockets;
• a floating seal assembly engaged with said partition and said first scroll member and isolating said discharge-pressure region from said suction-pressure region;
• and
• a modulation valve ring located axially between said floating seal assembly and said first end plate and being in sealing engagement with an outer radial surface of a hub extending from said first end plate and an outer radial surface of said floating seal assembly to define an axial biasing chamber in fluid communication with said biasing passage, said modulation valve ring being axially displaceable between first and second positions, said modulation valve ring abutting said first end plate and closing said modulation port when in said first position, said modulation valve ring abutting an axially facing surface of said floating seal assembly and spaced apart from said first end plate to open said modulation port when in said second position.