Wave motor

• US 6,045,339 A
• Filed: 01/20/1998
• Issued: 04/04/2000
• Est. Priority Date: 01/20/1998
• Status: Expired due to Fees

• Current Assignee: John L. Berg
• Original Assignee: John L. Berg
• Inventors: Berg, John L.
• Primary Examiner(s): Moulis, Thomas N.
• Assistant Examiner(s): GIMIE, MAHMOUD
• Application Number:
  US09/009,704
• Time in Patent Office: 805 Days
• Field of Search: 417/332, 417/331, 417/330, 417/333, 60/501, 60/500, 60/506, 60/505
• US Class Current: 417/332
• CPC Class Codes: F03B 13/1815 with an up-and-down movement
• CPC Class Codes: Y02E 10/30 Energy from the sea, e.g. using wave energy or salinity gradient

Abstract

A wave energy harvesting apparatus of the type employing laterally spaced-apart floats arranged so that the up and down movements of the floats in response to the wave motion are out of phase with each other and can be used to drive one or more pumps is configured to maintain a fixed orientation with respect to the direction of wave motion and is adapted, on the basis of local wave characteristics, to maximize the average power output. This adaptation may be provided by means including initial selection of the overall size of the apparatus and subsequent adjustments made to the pumping mechanism. The preferred pumping arrangement employs three pumps, each having a piston with one end removably pivotally attached to a pumping arm near one of the floats. Each piston reciprocates, with a stroke much longer than its diameter, within a respective neutrally buoyant cylinder that is pivotally attached to a body float.

Claims

1. In a wave energy harvesting machine of the type having a plurality of laterally spaced-apart floats arranged so that the up and down movements of the floats in response to wave motion on a body of water are out of phase with each other and can be used to drive a pump comprising a piston having a predetermined diameter, the piston reciprocating over a stroke length within a cylinder pivotally attached to one of the floats, the piston comprising a free end pivotally attached to a pumping arm connecting the one of the floats to a second float, an improvement comprising:

means for pivotally attaching the free end of the piston to the pumping arm adjacent the second float so that the stroke length is larger than the predetermined diameter of the piston; and

means for rendering the cylinder neutrally buoyant.

2. The improved wave energy harvesting machine of claim 1 wherein the means for attaching the free end of the piston to the pumping arm comprises a plurality of attachment points spaced along the pumping arm whereby the free end of the piston is adapted to be selectively movable from one attachment point to another so as to change the stroke length of the piston.

3. In a wave energy harvesting machine of the type having a plurality of laterally spaced-apart floats arranged so that the up and down movements of the floats in response to wave motion on a body of water are out of phase with each other and can be used to drive a pump comprising a piston having a predetermined diameter, the piston reciprocating over a stroke length within a cylinder pivotally attached to one of the floats, the piston comprising a free end pivotally attached to a pumping arm connecting the one of the floats to a second float, an improvement wherein the cylinder is adapted to be neutrally buoyant when the machine is disposed in the water.

4. The improved wave energy harvesting machine of claim 3 further comprising means for pivotally attaching the free end of the piston to the pumping arm adjacent the second float so that the stroke length is much larger than the predetermined diameter of the piston.

5. The improved wave energy harvesting machine of claim 4 wherein the means for attaching the free end of the piston to the pumping arm comprise a plurality of attachment points spaced along the pumping arm whereby the free end of the piston is adapted to be selectively movable from one of the attachment points to another so as to change the stroke length of the piston.

6. In a wave energy harvesting machine of the type comprising a main body supported by three main body floats, the machine adapted to be moored on a body of water by a mooring means attached to a front one of the three main body floats, the front main body float linked by a front pumping arm to a front pump arm float, each of the other two main body floats linked by a respective rear pumping arm to a respective rear pump arm float, each pumping arm hingedly connected adjacent one of its two ends to the respective pump arm float, each pumping arm hingedly connected adjacent the second of its two ends to the main body adjacent the respective main body float so that the up and down movements of the respective pump arm float and respective main body float can be used to drive a pump comprising a piston reciprocating within a cylinder pivotally attached to the main body adjacent the respective main body float, an improved selection of dimensions for adapting the machine to a predetermined wave trough-to-crest spacing wherein:

a first distance between a center of buoyancy of tie front pump arm float and a center of buoyancy of the front main body float is equal to the predetermined spacing;

a second distance, measured along a line drawn between the front pump arm float and the front main body float, between the front main body float and either of the other two main body floats is equal to the predetermined spacing; and

a third distance, measured along the line drawn between the front pump arm float and the front main body float, between a center of buoyancy of either of the other two main body floats and a center of buoyancy of the pump arm float respectively associated therewith is equal to the predetermined spacing.

7. The improved wave energy harvesting machine of claim 6 wherein all three of the pump arms have the same arm length, the arm length longer than the predetermined spacing.