Vibrational power generation device vibrator

• US 7,112,911 B2
• Filed: 01/30/2004
• Issued: 09/26/2006
• Est. Priority Date: 08/20/2003
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Tanaka, Hidetoshi, Ohkubo, Norio, Kanetomo, Masafumi
• Primary Examiner(s): Gonzalez, Julio C.
• Application Number:
  US10/767,438
• Publication Number:
  US 20050040654A1
• Time in Patent Office: 970 Days
• Field of Search: 310/323.01, 310/324, 310/325, 310/365, 310/328, 310/309, 310/308, 310/306, 735/143.2, 735/141.2
• US Class Current: 310/309
• CPC Class Codes: H02N 1/006 of the gap-closing type H02N1/004 takes precedence

Abstract

Unnecessary moment in a vibrator is remarkably reduced and the power generation efficiency in capacitance-type vibrational power generation is remarkably improved. A vibrator provided in a variable-capacitance type vibrator has a structure in that one ends of oscillation plates extending in a longitudinal direction thereof sandwiches a mass and the other ends thereof sandwiches a spacer, respectively, wherein the oscillation plates are arranged parallel to each other. A space portion between the oscillation plates and in which the mass and the spacer are not in contact with each other functions as a spring. By holding the mass by the two oscillation plates, the mass can be oscillated while it is in parallel to an opposing electrode. Therefore, generation of unnecessary moment in a direction other than an oscillation direction can be remarkably reduced.

Claims

1. A vibrational power generation device vibrator comprising:

first and second electrodes constituting a first capacitance;

third and fourth electrodes constituting a second capacitance;

a vibrator provided with said first and third electrodes;

an electrode base provided with said second and fourth electrodes;

a vibrator pedestal for fixing said vibrator onto said electrode base; and

an electrode terminal respectively connected to said first to fourth electrodes and performing an input and output of electric charges from the exterior,

wherein said vibrator includes a mass performing an undriven vibration and two oscillation plates for supporting said mass,

wherein said oscillation plates sandwich and support a first surface of said mass and a second surface opposite thereto in a mutually parallel manner, and

wherein said vibrator is operated through vibrational energy to change a capacitance by controlling a distance between said first and third electrodes and a distance between said second and fourth electrodes provided at said vibrator.

2. The vibrational power generation device vibrator according to claim 1,

wherein said first electrode is provided on a first surface of said vibrator,

wherein said third electrode is provided on a second surface of said vibrator facing said first surface,

wherein said second electrode is provided at said electrode base so as to face said first electrode, and

wherein said fourth electrode is provided at said electrode base so as to face said third electrode.

3. The vibrational power generation device vibrator according to claim 1,

wherein said first and third electrodes are provided on a first surface of said vibrator, and

wherein said second and fourth electrodes are provided at said electrode base so as to respectively face said first and third electrodes.

4. The vibrational power generation device vibrator according to claim 1,

wherein said first electrode is provided on a first surface of said vibrator,

wherein said third electrode is provided on a second surface of said vibrator facing said first surface,

wherein said second electrode is provided at said electrode base so as to face said first electrode,

wherein said fourth electrode is provided at said electrode base so as to face said third electrode, and

wherein said electrode base is provided with a contact prevention device for preventing contact between said first and third electrodes and said second and fourth electrodes at the time when said vibrator is operated through vibrational energy.

5. The vibrational power generation device vibrator according to claim 1,

wherein said first and third electrodes are provided on a first surface of said vibrator,

wherein said second and fourth electrodes are provided at said electrode base so as to respectively face said first and third electrodes, said electrode base comprising:

a contact prevention device for preventing contact between said first and third electrodes and said second and fourth electrodes at the time when said vibrator is operated through vibrational energy; and

an oscillation control structure for suppressing excessive vibration of said oscillation plates at the time when said vibrator is operated through vibrational energy.