Piezoelectric power generation system and sensor system

• US 7,176,601 B2
• Filed: 06/29/2004
• Issued: 02/13/2007
• Est. Priority Date: 09/05/2003
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ohkubo, Norio, Tanaka, Hidetoshi
• Primary Examiner(s): Schuberg; Darren
• Assistant Examiner(s): Aguirrechea; J.
• Application Number:
  US10/878,249
• Publication Number:
  US 20050052097A1
• Time in Patent Office: 959 Days
• Field of Search: 310/339
• US Class Current: 310/339
• CPC Class Codes: H02N 2/183 using impacting bodies high voltage generators in spark lighters F23Q

Abstract

A piezoelectric power generation system which performs a highly efficient power generation using a piezoelectric element without dependency on the direction of an externally driven vibration. The piezoelectric power generation system includes a vibrator having a beam in the form of a rod, and an impact element such as a steel ball. At one end of the beam is fixed the impact element, and at the other end of the beam, the beam is fixed to the base. The outer circumference of the impact element carries the cylinder shaped piezoelectric element. When the base vibrates due to an externally driven vibration, the vibrator vibrates in synchronization with the given vibration in the radial direction of the base to cause the impact element of the base to impact with the inner surface of the cylindrical piezoelectric element, forcing the piezoelectric element to deform and thereby generate electrical power. The dependency on the vibration direction in the vibrator is minimized to significantly improve the efficiency of power generation.

Claims

1. A sensor system comprising in a multilayered lamination:

a sensor to capture the information about a subject;

a piezoelectric power generation system to generate power due to vibration of said subject; and

a signal processing unit operating by the power generated by the piezoelectric power generation system to process and output the information obtained by the sensor;

wherein

said sensor is placed at a position nearest to said subject;

said piezoelectric power generation system is placed at a position furthest from said subject;

said signal processing unit is placed between said sensor and said piezoelectric power generation system.

2. A sensor system according to claim 1, wherein:

said piezoelectric power generation system comprises

a cylindrical piezoelectric element;

a vibrator including;

a beam in the form of a rod; and

an impact element fixed to one end of said beam to impact an inner circumference of said piezoelectric element; and

a base to fix another end of said beam;

wherein said piezoelectric element generates power by said impact element vibrating in an arbitrary circular direction perpendicular to a center axis of said piezoelectric element and impacting the inner circumference of said piezoelectric element.

3. A sensor system according to claim 1, wherein

said piezoelectric power generation system comprises

a cylindrical piezoelectric element;

a vibrator including;

a beam in the form of a rod; and

an impact element fixed to one end of said beam to impact an inner circumference of said piezoelectric element; and

a base to fix another end of said beam;

wherein said piezoelectric element generates power by said impact element vibrating in an arbitrary circular direction perpendicular to a center axis of said piezoelectric element and impacting the inner circumference of said piezoelectric element; and

wherein said sensor system is secured to a cylindrical attachment joint mounted to said subject with a thread formed on an outer circumference thereof so that a center axis of said sensor system is aligned with a center of axis of said attachment joint.

4. A sensor system according to claim 1, wherein:

said piezoelectric power generation system comprises;

a cylindrical impact wall;

a cylindrical piezoelectric element provided on an inner circumference of said impact wall;

a beam in the form of a rod, having said piezoelectric element fixed at one end; and

a base to fix another end of said beam;

wherein said piezoelectric element vibrates, forced by the vibration in an arbitrary circumferential direction perpendicular to the center axis of said piezoelectric element, to impact the inner circumference of said impact wall to generate electrical power.

5. A sensor system according to claim 1, wherein

said piezoelectric power generation system comprises:

a cylindrical impact wall;

a cylindrical piezoelectric element provided on the inner circumference of said impact wall;

a beam in the form of a rod, having said piezoelectric element fixed at one end; and

a base to fix another end of said beam;

wherein said piezoelectric element vibrates, forced by the vibration in an arbitrary circumferential direction perpendicular to a center axis of said piezoelectric element, to impact the inner circumference of said impact wall to generate electrical power, and wherein

said sensor system is secured to a cylindrical attachment joint mounted to said subject with a thread formed on an outer circumference thereof so that a center axis of said sensor system is aligned with a center axis of said attachment joint.