Actuator support structure and pump device

A pump device comprising:

• a plate-shaped actuator arranged to flexurally vibrate from a center portion of a principal surface thereof to an outer peripheral portion thereof;
• a housing including a side wall surrounding an outer periphery of the actuator and an opposed wall which is adjacent to and opposed to the principal surface of the actuator;
• and
• a plurality of elastic support portions elastically supporting the outer periphery of the actuator on the side wall, the plurality of elastic support portions being separately provided and spaced apart from one another around the outer periphery of the actuator;
• wherein
• the plate-shaped actuator includes a piezoelectric element configured to vibrate the actuator;
• the plate-shaped actuator includes a vibration plate that is a solid contiguous body;
• each of the elastic support portion includes:
• a beam portion extending in a gap between the actuator and the side wall in a circumferential direction along the outer periphery of the actuator;
• an actuator connection portion connecting the beam portion to the actuator;
• and
• a side wall connection portion connecting the beam portion to the side wall at a position offset from the actuator connection portion in the direction along the outer periphery of the actuator;
• and
• the side wall connection portions extend outward in a radial direction from the respective beam portion towards the side wall and are directly connected to the side wall;
• and
• the opposed wall includes a flow path hole in a center portion of a region facing the actuator or in an area surrounding the center portion through which a fluid flows.