1. An expander used in a refrigeration cycle using carbon dioxide as refrigerant and having a compressor, an outdoor heat exchanger and an indoor heat exchanger, wherein said expander comprises a cylindrical cylinder, a rotor which rotates in said cylinder, a vane which divides an expansion space formed between an inner peripheral surface of said cylinder and an outer peripheral surface of said rotor into a plurality of spaces, and a vane groove provided in said rotor for accommodating said vane therein, and wherein said vane groove is provided with a back pressure chamber which pushes said vane against the inner peripheral surface of said cylinder, and said refrigerant in the supercritical state is introduced into said back pressure chamber, wherein the expander is lubricated by oil mist discharged from the compressor.
2. An expander according to claim 1, further comprising a suction pipe which introduces refrigerant into said expansion space, wherein a portion of refrigerant flowing through said suction pipe is introduced into said back pressure chamber.
3. An expander according to claim 1, wherein no oil reservoir is provided in a hausing which includes said cylinder or said rotor therein.
4. A refrigeration cycle apparatus having a refrigeration cycle using carbon dioxide as refrigerant and having a compressor, an outdoor heat exchanger, an expander and an indoor heat exchanger, said refrigeration cycle apparatus including, in said refrigeration cycle, a first four-way valve to which a discharge side pipe and a suction side pipe of said compressor are connected, and a second four-way valve to which a refrigerant-inflow side pipe and a refrigerant-outflow side pipe of said expander are, connected, wherein using, as said expander, a sliding vane type expander having a cylindrical cylinder, a rotor which rotates in said cylinder, a vane which divides an expansion space formed between an inner peripheral surface of said cylinder and an outer peripheral surface of said rotor into a plurality of spaces, and a vane groove provided in said rotor for accommodating said vane therein, refrigerant flowing through a pipe extending from said second four-way valve to a refrigerant-inflow port of said expander is introduced into a back surface of said vane, wherein the expander is lubricated by oil mist discharged from the compressor.
5. A refrigeration cycle apparatus having a refrigeration cycle using carbon dioxide as refrigerant and having a compressor, an outdoor heat exchanger, an expander and an indoor heat exchanger, said refrigeration cycle apparatus including, in said refrigeration cycle, a first four-way valve to which a discharge side pipe and a suction side pipe of said compressor are connected, and a second four-way valve to which a refrigerant-inflow side pipe and a refrigerant-outflow side pipe of said expander are connected, wherein using, as said expander, a sliding vane type expander having a cylindrical cylinder, a rotor which rotates in said cylinder, a vane which divides an expansion space formed between an inner peripheral surface of said cylinder and an outer peripheral surface of said rotor into a plurality of spaces, and a vane groove provided in said rotor for accommodating said vane therein, refrigerant flowing through a pipe extending from a discharge port of said compressor to said first four-way valve is introduced into a back surface of said vane, wherein the expander is lubricated by oil mist discharged from the compressor.
6. A compressor used in a refrigeration cycle using carbon dioxide as refrigerant and having an outdoor heat exchanger and an indoor heat exchanger and an expander, wherein said compressor comprises a cylindrical cylinder, a rotor which rotates in sail cylinder, a vane which divides a compression space formed between an inner peripheral surface of said cylinder and an outer peripheral surface of said rotor into a plurality of spaces, and a vane groove provided in said rotor for accommodating said vane therein, and wherein said vane groove is provided with a back pressure chamber which pushes said vane against the inner peripheral surface of said cylinder, and said refrigerant in the supercritical state is introduced into said back pressure chamber, wherein the expander is lubricated by oil mist discharged from the compressor.
7. A compressor according to claim 6, further comprising a discharge pipe which discharges refrigerant from said compression space, wherein a portion of refrigerant flowing through said discharge pipe is introduced into said back pressure chamber.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A blade lock for blading an axial design turbine wherein the blades are inserted into an undercut blade groove of a turbine rotor in a positive-locking manner, the blade lock comprising:
a mounting space in connection with the blade groove;
a filler piece in positive-locking relationship with a blade foot of at least one of the blades;
a wedge inserted into said mounting space, said mounting space having a cross section receiving the filler piece that is conically widened beginning from the blade groove, said filler piece having a cross section adapted to said cross section of said mounting space.
2. A blade lock in accordance with claim 1, wherein said mounting space includes side walls extending at an angle to the blade groove.
3. A blade lock in accordance with claim 1, wherein said side walls of said mounting space form an angle with a longitudinal axis of the blade in an axial direction.
4. A blade lock in accordance with claim 2, wherein said side walls of said mounting space form an angle with a longitudinal axis of the blade in an axial direction.
5. A blade lock in accordance with claim 1, further comprising: stud screws in the turbine rotor wherein said wedge is secured by said stud screws in the turbine rotor.
6. A blade lock in accordance with claim 2, further comprising: stud screws in the turbine rotor wherein said wedge is secured by said stud screws in the turbine rotor.
7. A blade lock in accordance with claim 3, further comprising: stud screws in the turbine rotor wherein said wedge is secured by said stud screws in the turbine rotor.
8. A process for manufacturing a blade lock for blading an axial design turbine wherein the blades are inserted into an undercut blade groove of a turbine rotor in a positive-locking manner, the blade lock including a mounting space in connection with the blade groove, a filler piece in positive-locking relationship with a blade foot of at least one of the blades and a wedge inserted into the mounting space, the mounting space having a cross section receiving the filler piece that is conically widened beginning from the blade groove, the filler piece having a cross section adapted to the cross section of the mounting space, the process comprising the steps of:
preparing the blade groove by turning;
subsequent to said step of preparing the blade groove by turning, inserting the filler piece, which has been prepared except for the blade groove contour, into the prepared mounting space;
fixing the filler piece with the wedge;
milling the blade groove contour in the blade groove and at the same time milling the blade groove contour in the filler piece;
removing the filler piece and the wedge from the mounting space; and
equipping the turbine rotor with the blades and securing the blades in the blade groove by the blade lock.