Variable diffuser having a respective penny for each vane

A centrifugal compressor comprising:

• an impeller having a high pressure outlet;
• a scroll;
• and
• a variable diffuser between the impeller and the scroll, wherein high pressure gas flows from the high pressure outlet through the variable diffuser to the scroll, the variable diffuser comprising:
• a passage defined between opposing faces of a hub and a tip;
• at least two vanes within the passage, each of said vanes comprising a vane body having a leading edge and a trailing edge, the vane body extending between the hub face and the tip face;
• an actuator that includes an actuating ring;
• and
• at least two rotatable pennies, each of said pennies coupled to a respective vane body and the actuator, wherein each penny is coupled to the respective vane body near an edge of the penny, each penny having a drive shaft extending from a first face of the penny, said first face opposite a second face of the penny proximate the respective vane body, and wherein said actuating ring is coupled to each drive shaft via a respective coupling member, each penny configured to rotate about an axis defined by the respective drive shaft;
• and
• wherein rotation of at least one penny changes an orientation of the respective vane relative to the hub face,
• wherein each penny is rotatable a minimum of 90 degrees.

A method of varying fluid flow exiting a centrifugal compressor, the method comprising:

• defining a diffuser passage between a pair of axially displaced and opposing disk faces;
• fixing a plurality of vanes in the diffuser passage, each vane extending between the opposing disk faces and coupled to a respective penny housed in a first of the disk faces, each penny having a drive shaft extending from a face of the penny, the drive shaft defining an axis;
• coupling each drive shaft to an actuating member of an actuator via a coupling member;
• rotating each penny about the respective axis defined by the respective drive shaft when the actuating member is rotated by the actuator;
• and
• transitioning each of the plurality of vanes from a first orientation relative to the diffuser passage to a second orientation relative to the diffuser passage by rotating each respective penny in unison,
• wherein each coupling member includes an actuation slot and is coupled to the actuating ring by a pin that slides in the actuation slot to transmit movement by the actuating ring into rotation of each respective penny.