Semi-resonant motion devices and methods thereof
A semi-resonant actuator assembly includes a resonating body comprising a piezoelectric plate having a first length, a first width, and a first thickness, and an inactive plate having a second length substantially equal the first length, a second width substantially equal to the first width, and second thickness. A thickness of the resonating body is provided by a sum of the first thickness of the active piezoelectric plate and the second thickness of the inactive plate.
1. A semi-resonant actuator assembly comprising:
a resonating body comprising:
a single piezoelectric plate having a first length, a first width, and a first thickness, the piezoelectric plate having two independent active areas with corresponding external electrodes located on a single exterior surface of the piezoelectric plate; and
an inactive plate having a second length substantially equal the first length, a second width substantially equal to the first width, and a second thickness,
wherein a resonating body thickness of the resonating body is provided by a sum of the first thickness of the active piezoelectric plate and the second thickness of the inactive plate.
2. The semi-resonant actuator assembly as set forth in claim 1 , wherein the inactive plate is bonded to the piezoelectric plate.
3. The semi-resonant actuator assembly as set forth in claim 1 , wherein the inactive plate is formed from an inactive ceramic that is co-fired with the piezoelectric plate.
4. The semi-resonant actuator assembly as set forth in claim 1 further comprising:
at least one friction bump at an anti-node plane of the resonating body.
5. The semi-resonant actuator assembly as set forth in claim 1 , wherein the resonating body is rectangular in shape.
6. A semi-resonant actuator device comprising:
a semi-resonant actuator assembly comprising:
a resonating body comprising:
a single piezoelectric plate having a first length, a first width, and a first thickness, the piezoelectric plate having two independent active areas with corresponding external electrodes located on a single exterior surface of the piezoelectric plate; and
an inactive plate having a second length substantially equal the first length, a second width substantially equal to the first width, and a second thickness, wherein a resonating body thickness of the resonating body is provided by a sum of the first thickness of the active piezoelectric plate and the second thickness of the inactive plate; and
a two-phase drive circuit operably coupled to the piezoelectric plate of the semi-resonant actuator assembly.
7. The semi-resonant actuator device as set forth in claim 6 , wherein the two-phase drive circuit is operably coupled to the at least two independent active areas of the piezoelectric plate.
8. The semi-resonant actuator device as set forth in claim 7 , wherein the two-phase drive circuit comprises two full-bridge switching electronic circuits configured to produce two drive signals.
9. The semi-resonant actuator device as set forth in claim 8 , wherein the two full-bridge switching electronic circuits are configured to produce the two drive signals having adjustable frequency, phase, pulse width, and amplitude.
10. The semi-resonant actuator device as set forth in claim 7 , wherein the two full-bridge switching electronic circuits are configured to produce the two drive signals having a substantially equal frequency, wherein the frequency is less than a first bending resonance of the semi-resonant actuator assembly or greater than a second bending resonance of the semi-resonant actuator assembly.
11. A semi-resonant motion system comprising:
a semi-resonant actuator assembly comprising:
a resonating body comprising:
a single piezoelectric plate having a first length, a first width, and a first thickness, the piezoelectric plate having two independent active areas with corresponding external electrodes located on a single exterior surface of the piezoelectric plate; and
an inactive plate having a second length substantially equal the first length, a second width substantially equal to the first width, and a second thickness, wherein a resonating body thickness of the resonating body is provided by a sum of the first thickness of the active piezoelectric plate and the second thickness of the inactive plate;
a two-phase drive circuit operably coupled to the piezoelectric plate of the semi-resonant actuator assembly;
a flexible printed circuit board operably coupled to the external electrodes of the piezoelectric plate of the semi resonant actuator assembly and the two-phase drive circuit;
a preload spring positioned to support the semi-resonant actuator assembly; and
at least one movable body positioned between the semi-resonant actuator assembly and the at least one moveable body, wherein the preload spring provides a clamping force between the semi-resonant actuator assembly and the at least one movable body and frictionally connects the semi-resonant actuator assembly to the at least one moveable body.
12. The semi-resonant motion system as set forth in claim 11 , wherein the semi-resonant actuator assembly, the flexible printed circuit board, and the preload spring are assembled in a single plane using surface mount electronics assembly processes.
13. The semi-resonant motion system as set forth in claim 11 further comprising a second semi-resonant actuator assembly coupled in parallel to the two-phase drive circuit configured to produce vibration ellipses that frictionally engage the movable body such that forces generated by the at least two semi-resonant actuator assemblies substantially add together.
14. The semi-resonant motion device system as set forth in claim 13 , wherein the at least one moveable body is a linear movable body and the at least two semi-resonant actuator assemblies are clamped to opposite sides of the linear movable body and the two-phase drive circuit is configured to produce the rotation directions of the vibration ellipses in opposite directions.
15. The semi-resonant motion system as set forth in claim 13 , wherein the at least one movable body is rotatable movable body and the at least two semi-resonant actuator assemblies are clamped to opposite sides of a rotatable movable body and the two-phase drive circuit is configured to produce the rotation directions of the vibration ellipses in a same direction.
16. The semi-resonant actuator system as set forth in claim 13 , wherein the two full-bridge switching electronic circuits are configured to produce the two drive signals having a substantially equal frequency, wherein the frequency is less than a first bending resonance of the semi-resonant actuator assembly or greater than a second bending resonance of the semi-resonant actuator assembly.