Shaft coupling and arrangement for fluid machine and refrigeration cycle apparatus

A fluid machine comprising:

• a first rotating mechanism comprising a compression mechanism for compressing a fluid or an expansion mechanism for expanding fluid, the compression mechanism and the expansion mechanism having a first rotating shaft in which a first oil supply passage extending axially is formed;
• a second rotating mechanism comprising a compression mechanism for compressing a fluid or an expansion mechanism for expanding a fluid, the compression mechanism and the expansion mechanism having a second rotating shaft in which a second oil supply passage extending axially is formed, the second rotating shaft being coupled linearly to the first rotating shaft such that lubricating oil is allowed to flow through the first oil supply passage and the second oil supply passage and a gap is present in a coupling part of the first and second rotating shafts;
• a closed casing for accommodating the first and second rotating mechanism;
• and
• a bearing for supporting both the first and second rotating shafts, and covering a circumference of the gap in the coupling part of the first rotating shaft and the second rotating shaft in the closed casing, the bearing being fixed to the inner wall of the closed casing and the first and second rotating shafts being rotatable relative to the bearing, wherein the bearing comprises a single bearing member supporting both the first and second rotating shafts;
• wherein the first rotating shaft and the second rotating shaft are separate members from eachother;
• and
• wherein a first sliding part is disposed between the bearing and the first rotating shaft, and a second sliding part is disposed between the bearing and the second rotating shaft the gap in the coupling part of the first and second rotating shafts allowing lubricating oil to exit from the gap and be supplied to the sliding parts to lubricate and seal the sliding parts.