Natural-frequency adjusting mechanism for wave-power generator

Patent metadata

Field	Value
Publication number	US-9322388-B2
Application number	US-201214002189-A
Country	US
Kind code	B2
Filing date	Mar 15, 2012
Priority date	Mar 17, 2011
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

Provided is a wave-power generator capable of adjusting a natural period (natural frequency) in response to a changing wave period. The wave-power generator includes a weight that is installed in a floating body via a spring and that linearly reciprocates in response to a fluctuation of a water surface and a generator that generates power by being driven based on the linear reciprocating motion of the weight. An additional-mass body for adding a mass to the mass of the weight is further included.

First claim

The invention claimed is:

1. A wave-power generator comprising:
an oscillating body that is installed in a floating body via a spring and that linearly reciprocates in response to a fluctuation of a water surface;
a generator that generates power by being driven on the basis of the linear reciprocating motion of the oscillating body;
an additional-mass body for adding an additional mass to a mass of the oscillating body;
a conversion mechanism that converts the linear reciprocating motion of the oscillating body to rotational motion; and
a rotating body that is rotated by a torque extracted via the conversion mechanism,
wherein
the generator is provided at an upper end of the rotating body and is rotated by rotation of the rotating body to generate power,
the additional-mass body is attached to the rotating body, and
the additional-mass body is attached so as to be rotated together with the rotating body and is moved forward and backward with respect to water.

2. The wave-power generator according to claim 1 , wherein the additional mass of the additional-mass body is adjustable.

3. The wave-power generator according to claim 1 , wherein the additional-mass body is attached so as to be rotated together with the rotating body and includes a moving weight that can be moved in a radial direction from the center of rotation and a movement part for moving the moving weight in the radial direction.

4. The wave-power generator according to claim 1 , wherein the conversion mechanism is formed of a ball screw or is formed of a rack and a pinion.

5. The wave-power generator according to claim 1 , wherein a guide rail is provided in the floating body in the direction of the linear reciprocating motion, a ball is provided between the guide rail and the oscillating body, and the guide rail, the oscillating body, and the ball constitute a linear motion guide.

6. The wave-power generator according to claim 1 , further comprising an electric-power extracting mechanism that includes the oscillating body and the generator and has an axis in the direction of the linear reciprocating motion of the oscillating body,
wherein the electric-power extracting mechanism is placed such that the axis thereof matches a vertical axis that passes through the center of gravity of the floating body.

7. The wave-power generator according to claim 1 , further comprising an electric-power extracting mechanism that includes the oscillating body and the generator and has an axis in the direction of the linear reciprocating motion of the oscillating body,
wherein the electric-power extracting mechanism is placed such that the axis thereof is located at a position displaced from a vertical axis that passes through the center of gravity of the floating body, parallel to the vertical axis.

8. The wave-power generator according to claim 1 , further comprising an electric-power extracting mechanism that includes the oscillating body and the generator and has an axis in the direction of the linear reciprocating motion of the oscillating body,
wherein the electric-power extracting mechanism is placed such that the axis thereof is kept in a horizontal direction.

9. The wave-power generator according to claim 1 , further comprising an electric-power extracting mechanism that includes the oscillating body and the generator and has an axis in the direction of the linear reciprocating motion of the oscillating body,
wherein the electric-power extracting mechanism is placed such that the axis thereof is inclined with respect to the vertical direction.

10. The wave-power generator according to claim 1 , wherein the additional-mass body is provided with a blade whose base end portion is attached to the rotating body and that extends in a radial direction.

11. The wave-power generator according to claim 10 , wherein a pitch angle of the blade can be changed.

12. The wave-power generator according to claim 1 ,
wherein the additional-mass body is formed of a rotational plate-like body fixed to the rotating body; and
the rotational plate-like body is provided with a fin.

13. The wave-power generator according to claim 12 , wherein the fin can be moved forward and backward with respect to the rotational plate-like body.

14. A wave-power generator comprising:
a floating body that floats on a water surface;
an oscillating body that is installed in the floating body via a spring and that linearly reciprocates in response to a fluctuation of the water surface; and
a generator that generates power by being driven on the basis of the linear reciprocating motion of the oscillating body,
wherein
the floating body is provided with a projecting member projecting outward from a side thereof, and
a floating-body cross-sectional area at the water surface can be adjusted by changing an orientation of the projecting member, so that a floating-body spring coefficient of the floating body is adjustable.

15. The wave-power generator according to claim 14 , wherein a plurality of projecting members projecting outward from a side thereof are provided in the vertical direction.

16. The wave-power generator according to claim 14 , further comprising an additional-mass body for adding a mass to a mass of the oscillating body,
wherein the additional mass of the additional-mass body is adjustable.

17. The wave-power generator according to claim 14 ,
wherein a water accommodating portion for accommodating water is provided in the floating body; and
a holding water level in the water accommodating portion is adjustable.

18. The wave-power generator according to claim 17 , wherein a hydraulic pump is used as a pump that pumps water into the water accommodating portion from outside of the floating body and/or that discharges the water in the water accommodating portion to the outside of the floating body.

Assignees

• Hayashi Kentaro
• Yasunaga Takeshi
• Ikesue Shunichi
• Ohta Makoto
• Miura Masami
• Takamoto Yasuyoshi
• Kobayashi Yoshinori
• Hashimoto Hideaki
• Kaneko Shozo
• Hashimoto Akira
• Mitsubishi Heavy Ind Ltd
• Univ Tokyo

Inventors

• Hayashi Kentaro
• Yasunaga Takeshi
• Ikesue Shunichi
• Ohta Makoto
• Miura Masami
• Takamoto Yasuyoshi
• Kobayashi Yoshinori
• Hashimoto Hideaki
• Kaneko Shozo
• Hashimoto Akira

Classifications

• F03B15/00

  Controlling (controlling in general G05 {; regulation of plants characterised by the use of siphons F03B13/086}) · CPC title

• F05B2260/403

  through the shape of the drive components · CPC title

• F05B2270/18

  to control buoyancy · CPC title

• F05B2260/4031

  as in toothed gearing · CPC title

• F03B13/20 Primary

  wherein both members {, i.e. wom and rem} are movable relative to the sea bed or shore · CPC title