Patent attributes
A pump includes a first pump chamber formed by a first plate member and a second plate member, a second pump chamber formed by a first plate member and a third plate member, and a driving member. The driving member causes the first plate member to perform flexural vibration, thereby causing pressure changes in both of the first pump chamber and the second pump chamber. The first plate member is provided with first hole portions not overlapping an axial line orthogonal to a central region of the first plate member, and a check valve is provided to each of the first hole portions. The second plate member and the third plate member are provided with a second hole portion and a third hole portion respectively, and the check valve is provided to at least one of the second hole portion and the third hole portion.