Piezoelectric drive device, piezoelectric motor, and robot with the piezoelectric drive device
A piezoelectric drive device includes a piezoelectric element, a vibrating plate with a concave portion provided in a side surface, and a projecting portion provided between two side surfaces of the concave portion and having a spherical shape, an elliptical shape, or an egg shape, wherein a plurality of the piezoelectric elements and a plurality of the vibrating plates are stacked, and the concave portion includes a bottom surface.
1. A piezoelectric drive device comprising:
a plurality of piezoelectric elements;
a plurality of vibrating plates, each vibrating plate with a concave portion provided in a side surface; and
a projecting portion provided between two side surfaces of the concave portion and having a spherical shape or an elliptical shape or an egg shape, wherein
the plurality of piezoelectric elements and the plurality of vibrating plates are stacked, and
the concave portion includes a bottom surface,
wherein a depth of the concave portion is shallower than a length from a base end of the projecting portion to a top part at an opposite side to the base end and equal to or more than a half of the length from the base end to the top part.
2. The piezoelectric drive device according to claim 1 , wherein
a distance between the two side surfaces at the bottom surface is larger than a distance between the two side surfaces at an opposite side to the bottom surface.
3. The piezoelectric drive device according to claim 1 , wherein
a plurality of concave portions are provided in the plurality of vibrating plates, and
a depth of a concave portion in a vibration plate placed at a center in a stacking direction of the plurality of vibrating plates is deeper than a depth of a concave portion in an other vibration plate.
4. The piezoelectric drive device according to claim 3 , wherein
the plurality of concave portions are arranged in the stacking direction.
5. The piezoelectric drive device according to claim 3 , wherein
the plurality of concave portions are arranged in a direction crossing the stacking direction.
6. The piezoelectric drive device according to claim 1 , wherein
a plurality of concave portions are provided in the plurality of vibrating plates,
a convex portion being relatively convex is provided between two concave portions of the plurality of concave portions, and
a recessed portion that fits with the convex portion is provided in the projecting portion.
7. An ultrasonic motor comprising:
the piezoelectric drive device according to claim 1 ; and
a driven member driven by the piezoelectric drive device.
8. A robot comprising:
a plurality of link parts;
joint parts coupling the plurality of link parts; and
the piezoelectric drive device according to claim 1 that pivots the plurality of link parts by the joint parts.