Capacity control of rotary vane apparatus

A capacity control arrangement for a rotary vane fluid displacement apparatus which apparatus includes a housing having a reference axis, at least one endplate affixed to said housing to define therewith a compression chamber having an internal wall, a source of fluid at a pressure, a shaft extending through said housing, said shaft having an outer wall and an axis parallel to the reference axis, said shaft defining a blind-hole bore therein and a cross-drilled passage communicating between said blind-hole bore and said shaft outer wall, a rotor mounted on said shaft in said compression chamber, said rotor defining a front face, a rear face and a plurality of longitudinal guide slits, each slit having sidewalls with a root in proximity to said shaft, a plurality of slidable vanes, one of said vanes being disposed in each of said guide slits, each vane being operable between an extended working position and a retracted nonworking position, an inlet port and a discharge valve to provide ingress to and egress from said compression chamber for a compressible fluid, a control means, and means for selectively communicating a hydraulic control fluid at a pressure from said fluid pressure source through said blind-hole bore in response to said control means,

• a retaining means positioned in said rotor for each of said vanes to normally engage and maintain said vanes in said retracted nonworking position;
• said rotor defining a plurality of lateral passages, each lateral passage communicating between said rotor front face and one of said retaining means
• said retaining means being disengaged from maintaining said vanes in said retracted nonworking position by hydraulic control fluid above a predetermined pressure communicated through said lateral passage to allow said vanes to move to the extended working position;
• a face seal, defining a longitudinal bore with a side wall, is mounted and retained in said endplate in a fixed position, said face seal defining a face abutting the rotor and an arcuate recess in said face, said face seal further defining a fluid communicating passage in said bore side wall in register with said shaft cross-drilled passage, which fluid communicating passage provides communication between said cross-drilled passage and said arcuate recess, which arcuate recess communicates with each of said rotor lateral passages as said rotor rotates about the axis of said shaft to thereby provide hydraulic control fluid communication above a predetermined pressure to disengage said retaining means only when said rotor lateral passage to each retaining means is in register with said arcuate recess.

A capacity control arrangement for a rotary vane fluid displacement apparatus which apparatus includes a housing having a reference axis, at least one endplate affixed to said housing to define therewith a compression chamber having an internal wall, a source of fluid at a pressure, a shaft extending through said housing, said shaft having an outer wall and an axis parallel to the reference axis, said shaft defining a blind-hole bore therein and a cross-drilled passage communicating between said blind-hole bore and said shaft outer wall, a rotor mounted on said shaft in said compression chamber, said rotor defining a front face, a rear face and a plurality of longitudinal guide slits, each slit having sidewalls with a root in proximity to said shaft, a plurality of slidable vanes, one of said vanes being disposed in each of said guide slits, each vane being operable between an extended working position and a retracted nonworking position, an inlet port and a discharge valve to provide ingress to and egress from said compression chamber for a compressible fluid, a control means, and means for selectively communicating a hydraulic control fluid at a pressure from said fluid pressure source through said blind-hole bore in response to said control means,

• a retaining means positioned in said rotor for each of said vanes to normally engage and maintain said vanes in said retracted nonworking position;
• said retaining means being disengaged from maintaining said vanes in said retracted nonworking position by hydraulic control fluid above a predetermined pressure communicated to said guide slit root to allow said vanes to move to the extended working position;
• a face seal, defining a longitudinal bore with a side wall, is mounted and retained in said endplate in a fixed position, said face seal defining a face abutting the rotor and an arcuate recess in said face, said face seal further defining a fluid communicating passage in said bore side wall in register with said shaft cross-drilled passage, which fluid communicating passage provides communication between said cross-drilled passage and said arcuate recess, which arcuate recess communicates with each root of said guide slits as said rotor rotates about the axis of said shaft to thereby provide hydraulic control fluid communication above a predetermined pressure to disengage said retaining means from said vanes only when said guide slit root is in register with said arcuate recess.