초록 ▼

The present invention combines bending mode mechanical (frm) and electrical (fre) resonances, whereby a relatively good efficiency can be achieved within a relatively broad frequency range (Δf3). An electrical resonance (f rc) or mechanical resonance is designed to be situated in the same order

The present invention combines bending mode mechanical (frm) and electrical (fre) resonances, whereby a relatively good efficiency can be achieved within a relatively broad frequency range (Δf3). An electrical resonance (f rc) or mechanical resonance is designed to be situated in the same order of magnitude as another mechanical resonance (frm), but separated therefrom. Preferably, the separation (Δf2) is smaller than 2f1/Q1, where f1 is the resonance frequency for the resonance having lowest quality value, and Q1 is the corresponding quality value of the mechanical resonance. An electromechanical motor comprising a driving element and electrical resonance circuit according to the above ideas may comprise a double bimorph driving element having one single actuating point influencing a body to be moved. The double bimorph driving element is excited in bending vibrations perpendicular to a main displacement direction, whereby both tangential and perpendicular motions are created by bending mode vibrations.

대표청구항 ▼

The invention claimed is: 1. Electromechanical motor system comprising: a motor assembly having electromechanical driving element; said electromechanical driving element being arranged to actuate in both tangential and perpendicular direction on a body to be moved by use of essentially only bendin

The invention claimed is: 1. Electromechanical motor system comprising: a motor assembly having electromechanical driving element; said electromechanical driving element being arranged to actuate in both tangential and perpendicular direction on a body to be moved by use of essentially only bending modes; and a drive control connected to said electromechanical driving element; said electromechanical driving element having at least a first mechanical bending mode resonance and a second mechanical bending mode resonance, each of which having an associated resonance frequency; said first mechanical bending mode resonance frequency having a value in the same order of magnitude as said second mechanical bending mode resonance frequency; said first mechanical bending mode resonance frequency being separated from said second mechanical bending mode resonance frequency with a frequency separation smaller than 2fr1/Q1, Q 1being the lowest quality value among quality values of said first mechanical bending mode resonance and said second mechanical bending mode resonance, respectively, fr1 being a resonance frequency of the resonance having the quality value of Q1; said first mechanical bending mode having a stroke direction parallel to a stroke direction of said second bending mode; said electromechanical driving element being supported by pivot supports, allowing ends of said electromechanical driving element to move; said driving element having only one single actuating portion for interacting with said body to be moved; and said driving element having a main extension essentially parallel to a main displacement direction of said body to be moved. 2. Electromechanical motor system according to claim 1, wherein said drive control in turn comprises a voltage supply and an inductive element forming an electrical resonance circuit together with said electromechanical driving element, said electrical resonance circuit having an electrical resonance frequency in the same order of magnitude as at least one of said first and said second mechanical bending mode resonance frequencies. 3. Electromechanical motor system comprising: a motor assembly having electromechanical driving element; said electromechanical driving element being arranged to actuate in both tangential and perpendicular direction on a body to be moved by use of essentially only bending modes; and a drive control connected to said electromechanical driving element; said electromechanical driving element having at least a first mechanical bending mode resonance and a second mechanical bending mode resonance, each of which having an associated resonance frequency; said first mechanical bending mode resonance frequency having a value in the same order of magnitude as said second mechanical bending mode resonance frequency; said first mechanical bending mode having a stroke direction parallel to a stroke direction of said second bending mode; said electromechanical driving element being supported by pivot supports, allowing ends of said electromechanical driving element to move; wherein said drive control in turn comprises a voltage supply and an inductive element forming an electrical resonance circuit together with said electromechanical driving element, said electrical resonance circuit having an electrical resonance frequency in the same order of magnitude as at least one of said first and said second mechanical bending mode resonance frequencies, and wherein said electrical resonance frequency is situated between said first mechanical bending mode resonance frequency and said second mechanical bending mode resonance frequency. 4. Electromechanical motor system according to claim 1, wherein said driving element has a first bimorph section and a second bimorph section. 5. Electromechanical motor system according to claim 4, wherein said drive control is arranged to supply said first bimorph section with a first drive voltage and to supply said second bimorph section with a second drive voltage, said first and second drive voltages having the same frequency and being phase shifted relative to each other. 6. Electromechanical motor system according to claim 5, wherein said first and second bimorph sections have a main extension essentially parallel to a main displacement direction of said body, said single actuating portion being arranged substantially between said first and second bimorph sections, whereby said first mechanical resonance frequency is an odd order bending mode of said driving element perpendicular to said main displacement direction, said odd order bending mode having a motion antinode in a vicinity of said actuating portion, and said second mechanical resonance frequency is an even order bending mode of said driving element perpendicular to said main displacement direction, said even order bending mode having a motion node in said vicinity of said actuating portion. 7. Electromechanical motor system according to claim 6, wherein said first and second bimorph sections are supported against a means providing stiffness in said main displacement direction by said pivot supports, said pivot supports being arranged on each side, in the main displacement direction, of said actuating portion, whereby contact points between said pivot supports and said means providing stiffness are positioned off a symmetry axis of said driving element. 8. Method of operating an electromechanical motor system having a motor assembly in turn having electromechanical driving element, and a drive control connected to said electromechanical driving element, comprising the steps of: supplying voltage signals from said drive control to said electromechanical driving element; said voltage signals causing said electromechanical driving element to actuate in both tangential and perpendicular direction a body to be moved by use of essentially only bending modes; supporting said electromechanical driving element on pivot supports, allowing ends of said electromechanical driving element to move; said electromechanical driving element having only one single actuating portion for interacting with said body to be moved; said electromechanical driving element having a main extension essentially parallel to a main displacement direction of said body to be moved; said driving element having at least a first mechanical bending mode resonance with an associated first mechanical bending mode resonance frequency and a second mechanical bending mode resonance with an associated second mechanical bending mode resonance frequency; said first mechanical bending mode having a stroke direction parallel to a stroke direction of said second bending mode; and tuning at least one of said first mechanical bending mode resonance frequency and said second mechanical bending mode resonance frequency to assume values in the same order of magnitude as each other; said step of tuning comprising the step of providing a minor frequency separation between said first mechanical bending mode resonance frequency and said second mechanical bending mode resonance frequency; said frequency separation being smaller than 2fr1 /Q1, where Q1 being the lowest quality value among quality values of said first mechanical bending mode resonance and said second mechanical bending mode resonance, respectively, fr1 being a resonance frequency of the resonance having the quality value of Q1. 9. Method according to claim 8, wherein said step of tuning comprises the step of adjusting a force pressing said electromechanical driving element and said body to be moved together. 10. Method according to claim 8, wherein said first mechanical bending mode has a stroke direction parallel to a stroke direction of said second bending mode. 11. Method according to claim 8, wherein said electrical resonance frequency is situated between said first mechanical bending mode resonance frequency and said second mechanical bending mode resonance frequency.