Electric turbo compressor

An electric turbo compressor comprising:

• a housing;
• an electric motor accommodated in the housing;
• a rotary shaft accommodated in the housing, and driven to rotate by the electric motor;
• and
• a first impeller and a second impeller rotating together with the rotary shaft, wherein
• the electric motor, the first impeller, and the second impeller are arranged in this order in an axial direction of the rotary shaft,
• the first impeller includes a first hub fixed to the rotary shaft, and a plurality of first blades arranged on the first hub,
• the second impeller includes a second hub fixed to the rotary shaft, and a plurality of second blades arranged on the second hub,
• the first impeller rotates to move gas from a first leading end to a first trailing end of each of the plurality of first blades, wherein the first trailing end is a first edge portion of each of the plurality of first blades, and the first edge portion extends in the axial direction of the rotary shaft,
• the second impeller rotates to move the gas moved by the first impeller from a second leading end to a second trailing end of each of the plurality of second blades, wherein the second trailing end is a second edge portion of each of the plurality of second blades, and the second edge portion extends in the axial direction of the rotary shaft,
• the housing includes:
• a first shroud facing the first blades and forming a first impeller chamber that accommodates the first impeller;
• and
• a second shroud facing the second blades and forming a second impeller chamber that accommodates the second impeller,
• a gap between the first edge portion of each of the first blades and the first shroud is a first trailing end gap that has a shortest distance between each of the first blades and the first shroud in the axial direction, and a gap between the second edge portion of each of the second blades and the second shroud is a second trailing end gap that has a shortest distance between each of the second blades and the second shroud in the axial direction, and
• the first edge portion faces a first diffuser passage that is a first outlet of the first impeller chamber and downstream of the first trailing end of the first blades in a radial direction of a gas movement,
• the second edge portion faces a second diffuser passage that is a second outlet of the second impeller chamber and downstream of the second trailing end of the second blades in the radial direction of the gas movement, and
• the shortest distance of the first trailing end gap is smaller than the shortest distance of the second trailing end gap.