| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain an ultrasonic motor capable of releasing fixation of a stator and a rotor without giving any unnecessary load to the motor. <P>SOLUTION: An AC voltage represented by V<SB>0</SB>cos(ωt) is applied to a second vibration member 320 when an AC power supply 42 is directly connected to a second application electrode by a switch 25, under the condition of the AC power supply 42 energized at the voltage level of V<SB>0</SB>cos(ωt). In this case, an amplitude At obtained by adding the amplitude Aa at the (A) region of a piezoelectric material 19 and the amplitude Ab at the (B) region is expressed as follows: At=(√2)A<SB>0</SB>sin(2πx/λ+π/4)cos(ωt). This equation shows a standing wave with the amplitude of (√2)A<SB>0</SB>. Consequently, when the AC power supply 42 is directly connected to the second application electrode 24 by the switch 25, the piezoelectric material 19 is vibrated with √2 times higher amplitude than the case that the AC power supply 42 is connected to a phase shifter 41 by the switch 25. <P>COPYRIGHT: (C)2011,JPO&INPIT |
