Actuator

An actuator that moves a mover along a supporting member, comprising:

• a tubular supporting member;
• a mover arranged to relatively move in an axial direction of the supporting member along an inner surface of the supporting member, the mover including
• a tubular piezoelectric element,
• a first electrode provided on an inner surface of the piezoelectric element, and
• a vibrator, wherein both ends of the vibrator are fixed to an outer surface of the piezoelectric element and a central portion of the vibrator is arranged to be in contact with the supporting member;
• and
• a power supply unit arranged to apply a voltage to the first electrode and the vibrator,
• wherein the voltage is applied across the first electrode and the vibrator to generate a standing wave in the piezoelectric element, the vibration of the piezoelectric element is amplified by the vibrator, which thereby moves the mover in the axial direction of the supporting member.

An actuator that moves a mover along a supporting member, comprising:

• a tubular supporting member;
• a mover arranged to move in an axial direction of the supporting member along an inner surface of the supporting member, the mover including
• a tubular piezoelectric element,
• a first electrode provided at one end portion of an inner surface of the piezoelectric element, and
• a second electrode provided at the other end potion of the inner surface of the piezoelectric element, and
• a vibrator, wherein one end of the vibrator is fixed to an outer surface of the piezoelectric element facing the first electrode, the other end of the vibrator is fixed to the outer surface of the piezoelectric element facing the second electrode, and a central portion of the vibrator which is arranged to be in contact with the supporting member;
• and
• a power supply unit arranged to apply a voltage to the first electrode, the second electrode, and the vibrator,
• wherein a combined wave of a first vibration voltage that causes the piezoelectric element to shrink or expand in the axial direction and an intermittent second vibration voltage that has a same frequency as a natural frequency of the vibrator at a time of an expansion of the piezoelectric element is alternately applied across the first electrode and the vibrator and across the second electrode and the vibrator to vibrate the piezoelectric element, the vibration of the piezoelectric element is amplified by the vibrator, which thereby moves the mover in the axial direction of the supporting member.

An actuator that moves a mover along a supporting member, comprising:

• a tubular supporting member;
• a mover arranged to move in an axial direction of the supporting member along an inner surface of the supporting member, the mover including
• a tubular piezoelectric element,
• a first electrode provided at one end portion of an inner surface of the piezoelectric element, and
• a second electrode provided at the other end portion of the inner surface of the piezoelectric element,
• a third electrode provided at a central portion of the inner surface of the piezoelectric element, and
• a vibrator, wherein one end of the vibrator is fixed to an outer surface of the piezoelectric element facing the first electrode, the other end of the vibrator is fixed to the outer surface of the piezoelectric element facing the second electrode, and a central portion of the vibrator is arranged to be in contact with the supporting member;
• and
• a power supply unit arranged to apply a voltage to the first electrode, the second electrode, the third electrode, and the vibrator,
• wherein a combined wave of a first vibration voltage that causes the piezoelectric element to shrink or expand in the axial direction and an intermittent second vibration voltage that has a same frequency as a natural frequency of the vibrator at a time of an expansion of the piezoelectric is alternately applied across the first electrode and the vibrator, across the second electrode and the vibrator, and across the third electrode and the vibrator to vibrate the piezoelectric element, the vibration of the piezoelectric element is amplified by the vibrator, which thereby moves the mover in the axial direction of the supporting member.

An actuator that moves a mover along a supporting member, comprising:

• a tubular supporting member;
• a mover arranged to move in an axial direction of the supporting member along an inner surface of the supporting member, the mover including
• a tubular piezoelectric element,
• a first electrode provided at one end portion of an inner surface of the piezoelectric element, and
• a vibrator, wherein one end of the vibrator is fixed to an outer surface of the piezoelectric element facing the first electrode and the other end of the vibrator is arranged to be in contact with the supporting member;
• and
• a power supply unit arranged to apply a voltage to the first electrode and the vibrator,
• wherein a combined wave of a first vibration voltage that causes the piezoelectric element to shrink or expand in the axial direction and an intermittent second vibration voltage that has a same frequency as a natural frequency of the vibrator at a time of an expansion of the piezoelectric element is applied across the first electrode and the vibrator to vibrate the piezoelectric element, the vibration of the piezoelectric element is amplified by the vibrator, which thereby moves the mover in the axial direction of the supporting member.

An actuator that moves a mover along a supporting member, comprising:

• a tubular supporting member;
• a mover arranged to relatively move along an inner surface of the supporting member, the mover including
• a cylindrical vibrator, wherein one end portion and the other end portion of the vibrator are arranged to be in contact with an inner surface of the supporting member at a middle portion, a piezoelectric element arranged on the inner surface of the vibrator and a first electrode fixed to the inner surface of the piezoelectric element are provided at the one end portion, and a piezoelectric element arranged on the inner surface of the vibrator and a second electrode fixed to the inner surface of the piezoelectric element are provided at the other end portion;
• a power supply unit arranged to apply a voltage to the first electrode, the second electrode, and the vibrator,
• wherein a voltage is applied across the first electrode and the vibrator and a voltage is applied across the second electrode and the vibrator to vibrate the piezoelectric element, the vibration of the piezoelectric element is amplified by the vibrator, which thereby moves the mover along the supporting member.

An actuator that moves a mover along a supporting member, comprising:

• a cylindrical member or a columnar member supporting member;
• a mover arranged to relatively move along an outer surface of the supporting member, the mover including
• a cylindrical vibrator, wherein one end portion and the other end portion of the vibrator are arranged to be in contact with an inner surface of the supporting member at a middle portion, a piezoelectric element arranged on an outer surface of the vibrator and a first electrode fixed to the outer surface of the piezoelectric element are provided at the one end portion, and a piezoelectric element arranged on the outer surface of the vibrator and a second electrode fixed to the outer surface of the piezoelectric element are provided at the other end portion;
• a power supply unit arranged to apply a voltage to the first electrode, the second electrode, and the vibrator,
• wherein a voltage is applied across the first electrode and the vibrator and a voltage is applied across the second electrode and the vibrator to vibrate the piezoelectric element, the vibration of the piezoelectric element is amplified by the vibrator, which thereby moves the mover along the supporting member.