Piezoelectric elements (1) are overlapping on a stator (11) in the same
direction as shown in FIG. 3. Since a fixed end (6) of a piezoelectric
element (1) is fixed to a foundation (4), an open end (7) of the
piezoelectric element (1) elongates in the direction opposite to the
foundation (4) when a voltage is applied to the piezoelectric element (1).
When a drive device (12) generates a saw-tooth wave shown in FIG. 4(a),
the piezoelectric element (1) rapidly elongates or slowly shrinks. A
slider (21) then moves while being flicked away by the piezoelectric
element (1). On the other hand, since piezoelectric element (1) rapidly
shrinks or slowly elongates in the case of FIG. 4(b), a slider (21) moves
while being pulled in by the piezoelectric element (1). Because of
piezoelectric elements (1) arranged in a circle as shown in FIG. 13, a
stator (11) can rotate a circular rotor (31) and a spherical rotor (35).
