Abstract: In a centrifugal machine for a refrigeration or air conditioning system and including a casing, an impeller, a variable width diffuser assembly leading from the impeller, and a plurality of vanes received through respective complementary-shaped openings in a movable wall member, there is provided a sealing means in the openings between the vanes and movable wall member for preventing leakage of fluid through the openings, thereby increasing the operating efficiency of the machine.

Abstract: A centrifugal machine having a variable diffuser that includes a radially disposed fixed wall and an opposed movable wall defining the diffuser passage. Guideways are formed in the movable wall in which a series of diffuser vanes are slidably mounted. A spring biased retainer loosely holds each of the vanes in an associated guideway and urges the vanes into seating contact with the fixed wall so that each vane can adjust its position in assembly to accommodate for changes in diffuser alignment due to thermal growth or the like.

Abstract: A diffuser control for controlling vapor flow through a diffuser passage comprising an annular recess defined by a housing of the diffuser passage and in communication therewith, and an annular control ring supported for movement within the recess and the diffuser passage between a throttling position, wherein the restriction means throttles vapor flow through the diffuser passage, and an open position for permitting a substantially free flow of vapor through the diffuser passage. The diffuser control further comprises a plurality of springs supported by the housing for urging the control ring toward the throttling position, a stop for limiting movement of the control ring at the throttling position, a low pressure conduit for connecting the annular recess to a low pressure source, and a seal for retarding vapor flow from a higher pressure side of the control ring to a lower pressure side thereof when the control ring is in the open position.

Abstract: A diffuser control for controlling vapor flow through a diffuser passage comprising an annular recess defined by a housing of the passage and in communication therewith, a diffuser control ring supported for movement within the annular recess and the diffuser passage between a full throttling position, wherein the restriction means throttles vapor flow through the diffuser passage, and an open position for permitting a substantially free flow of vapor through the diffuser passage. The control further comprises a first set of springs for urging the control ring toward the full throttling position, and a second set of springs for urging the control ring toward an intermediate throttling position located between the open and full throttling positions. The diffuser control also comprises a low pressure conduit for connecting the annular recess to a low pressure source, and a intermediate pressure conduit for connecting the annular recess to an intermediate pressure source.