초록 ▼

The compression capacity of a rotary compressor may be changed by a cylinder bypass system. The change of compression capacity is achieved by a slide wall member which composes part of an inside wall of a cylinder containing a compression mechanism and which is movable, thereby bypassing gas being c

The compression capacity of a rotary compressor may be changed by a cylinder bypass system. The change of compression capacity is achieved by a slide wall member which composes part of an inside wall of a cylinder containing a compression mechanism and which is movable, thereby bypassing gas being compressed to a suction side of the compressor. The slide wall member is caused to slide forward by gas pressure applied and to slide backward by a spring force. By controlling such gas pressure, the capacity of the compressor may be changed. A relatively large opening is formed in the cylinder when the slide wall member is moved backward, so that the compression capacity can be greatly reduced without a large decrease in efficiency.

대표청구항 ▼

1. In a rotary compressor of the type including a cylinder block having therein a cylinder having a vertical axis, upper and lower bearing members having flanges with radially extending surfaces closing upper and lower ends of said cylinder, a suction port opening into said cylinder for introducing

1. In a rotary compressor of the type including a cylinder block having therein a cylinder having a vertical axis, upper and lower bearing members having flanges with radially extending surfaces closing upper and lower ends of said cylinder, a suction port opening into said cylinder for introducing therein gas to be compressed, a rotor mechanism rotatable within said cylinder for compressing said gas, a discharge port extending from said cylinder for discharging therefrom the compressed gas, and means for changing the compression capacity of said compressor, the improvement wherein said means comprises: an opening formed in said flange of one of said bearing members, said opening extending from the respective said radially extending surface into said flange in a depth direction parallel to said axis, and said opening facing a portion of the respective said end of said cylinder and a portion of a respective end surface of said cylinder block; a slide wall member mounted within said opening for sliding movement in opposite directions at right angles to said axis between a first position, whereat the slide wall member opens communication between said opening and said end portion of said cylinder, and a second position, whereat said slide wall member blocks communication between said opening and said end portion of said cylinder; spring means mounted within said opening for biasing said slide wall member in a first said direction to said first position; a control port extending into said opening at a location on a side of said slide wall member opposite said end portion of said cylinder; and valve means for selectively introducing into said control port compressed gas from said discharge port, thereby sliding said slide wall member in said opening in a second said direction opposite the force of said spring means to said second position, thus blocking communication between said cylinder end portion and said opening and providing a relatively larger compression capacity of said cylinder, and for selectively interrupting introduction into said control port of compressed gas from said discharge port, whereby said spring means slides said slide wall member in said opening in said first direction to said first position, thus opening communication between said cylinder end portion and said opening and providing a relatively smaller compression capacity of said cylinder. 2. The improvement claimed in claim 1, wherein said slide wall member has formed therein a concave recess receiving and housing at least a portion of said spring means. 3. The improvement claimed in claim 1, wherein said spring means comprises a coil spring which has a configuration flattened in a dimension parallel to said axis. 4. The improvement claimed in claim 1, wherein said slide wall member has a planar end surface which abuts with a planar surface defining said opening when said slide wall member is in said second position. 5. The improvement claimed in claim 1, wherein said opposite first and second directions extend radially of said axis. 6. The improvement claimed in claim 1, wherein said opening is formed in said flange of said lower bearing member. 7. The improvement claimed in claim 1, wherein said opening extends axially entirely through said flange, and further comprising a cover plate closing the end of said opening opposite said cylinder. 8. The improvement claimed in claim 1, wherein said spring means comprises a coil spring which has a configuration flattened in a dimension parallel to said axis, said slide wall member has formed therein a concave recess receiving and housing at least a portion of said coil spring, said slide wall member has a planar end surface which abuts with a planar surface defining said opening when said slide wall member is in said second position, said opposite first and second directions extend radially of said axis, said opening extends axially entirely through said flange of said lower bearing member, and further comprising a cover plate closing the lower end of said opening. 9. The improvement claimed in claim 1, further comprising a by-pass port extending through said cylinder block and opening onto said end surface portion thereof, and said cylinder end portion communicates with said by-pass port through said opening when said slide wall member is in said first position. 10. The improvement claimed in claim 9, wherein said valve means comprises means for, upon said interruption of the introduction of compressed gas into said control port, connecting said by-pass port to said suction port.