초록 ▼

A low pressure-side first-stage compressor impeller and a high pressure-side second-stage compressor impeller are mounted respectively on opposite ends of a rotation shaft. A rotor of an electric motor for driving the two impellers is formed at a central portion of the rotation shaft. A stator of th

A low pressure-side first-stage compressor impeller and a high pressure-side second-stage compressor impeller are mounted respectively on opposite ends of a rotation shaft. A rotor of an electric motor for driving the two impellers is formed at a central portion of the rotation shaft. A stator of the motor is held by a motor casing. The motor casing, a first-stage compressor casing, which cooperates with the first-stage compressor impeller to form a first-stage compressor, and a second-stage compressor casing, which cooperates with the second-stage compressor impeller to form a second-stage compressor, are cast into an integral construction. This integral casing is further formed integrally with an intermediate cooler, disposed downstream of the first-stage compressor, and a discharge cooler disposed downstream of the second-stage compressor. The intermediate cooler and the discharge cooler are disposed below the motor casing in generally parallel relation to the rotation shaft, and the main portions of the two-stage centrifugal compressor are combined into a compact, generally rectangular parallelepiped configuration.

대표청구항 ▼

[What is claimed is:] [1.]two centrifugal impellers mounted respectively on opposite ends of a rotation shaft to form upstream-side and downstream-side compressor stages;an electric motor portion for directly driving said two impellers, said motor portion being formed at a central portion of said ro

[What is claimed is:] [1.]two centrifugal impellers mounted respectively on opposite ends of a rotation shaft to form upstream-side and downstream-side compressor stages;an electric motor portion for directly driving said two impellers, said motor portion being formed at a central portion of said rotation shaft;a motor casing covering said motor portion; andcompressor casings covering said compressor stages, respectively;wherein said motor casing and said compressor casings are cast into an integral construction to form an integral casing, an intermediate cooler is provided between said compressor stages, and a discharge cooler is provided downstream of the downstream-side compressor stage, and a shell of said two coolers is formed integrally with said integral casing.