Pump device and method of manufacturing the same

A pump device comprising:

• a motor that comprises a rotor and a stator having an annular shape surrounding an outer periphery of the rotor;
• a first housing that seals the stator;
• a second housing that is put on the first housing from one side in an axial direction along a rotation axis of the rotor to form a pump chamber between the first housing and the second housing;
• and
• an impeller that is disposed in the pump chamber and rotates integrally with the rotor,
• wherein
• the first housing comprises:
• a first partition wall portion that covers the stator on the one side in the axial direction,
• a trunk portion that covers an outer periphery of the stator, and
• a first flange portion having an annular shape that protrudes from the trunk portion toward an outer peripheral side, the first flange portion is provided with a first welding portion on a surface thereof facing the one side in the axial direction, the second housing comprises:
• an end plate portion that is opposed to the first partition wall portion from the one side in the axial direction,
• a side wall portion that extends from an outer peripheral edge of the end plate portion toward another side in the axial direction,
• a second flange portion having an annular shape that protrudes from the side wall portion toward the outer peripheral side,
• a first tubular portion that extends from a center of the end plate portion toward the one side in the axial direction, and
• a second tubular portion that extends from the side wall portion toward a direction intersecting the axial direction, the second flange portion is provided with a second welding portion that is welded to the first welding portion on a surface thereof facing the other side in the axial direction,
• wherein the second housing is provided with a plurality of first reinforcement ribs respectively provided at a plurality of positions in a circumferential direction, each of the plurality of first reinforcement ribs connecting the side wall portion and the second flange portion.