Fluid machine

A fluid machine, comprising:

• a rotary shaft;
• an electric motor configured to rotate the rotary shaft;
• a housing including a motor chamber that accommodates the electric motor, an inlet hole through which fluid is drawn into the motor chamber, an impeller chamber, and a discharge chamber;
• an impeller that causes the fluid to be drawn from the motor chamber into the impeller chamber and discharged from the impeller chamber into the discharge chamber, by rotation of the rotary shaft;
• a dynamic thrust bearing rotatably supporting the rotary shaft in a thrust direction;
• a thrust bearing support supporting the dynamic thrust bearing;
• and
• a support plate protruding radially outward in an annular shape from a portion of an outer peripheral surface of the rotary shaft, wherein the support plate is located between the impeller and the electric motor, and configured to rotate integrally with the rotary shaft,
• the thrust bearing support including:
• a first bearing base disposed closer to the electric motor than the support plate is and having a first through hole through which the rotary shaft extends;
• and
• a second bearing base disposed closer to the impeller than the support plate is and having a second through hole through which the rotary shaft extends, and
• the dynamic thrust bearing including:
• a first dynamic thrust bearing disposed between the first bearing base and the support plate and rotatably supporting the rotary shaft in the thrust direction;
• and
• a second dynamic thrust bearing disposed between the second bearing base and the support plate and rotatably supporting the rotary shaft in the thrust direction, wherein
• the thrust bearing support includes a spacer member disposed on an outer side of the support plate in a radial direction of the rotary shaft and interposed between the first bearing base and the second bearing base,
• the first bearing base and the second bearing base are fixed to each other via the spacer member, and
• inside the housing:
• a main passage is formed, through which the fluid flows from the motor chamber toward the impeller chamber while passing outside the first bearing base, the spacer member, and the second bearing base,
• the first through hole communicates with the motor chamber,
• the second through hole communicates with the main passage,
• a space is formed between an inner side of the spacer member in the radial direction of the rotary shaft and an outer side of the first dynamic thrust bearing and the second dynamic thrust bearing in the radial direction of the rotary shaft, wherein the space communicates with the first through hole through a clearance between the first dynamic thrust bearing and the support plate and communicates with the second through hole through a clearance between the second dynamic thrust bearing and the support plate,
• the thrust bearing support includes a connecting passage interconnecting the space and the main passage, and
• fluid in the space located between the inner side of the spacer member and the outer side of the first dynamic thrust bearing and the second dynamic thrust bearing flows from the space to the main passage via the connecting passage.