Device for generating electrical energy from a vibrating tool

Abstract

A device for generating electrical energy from the vibrations generated by a well bore drill tool during the operation of the tool when drilling oil wells, the device comprising an array of piezoelectric elements mounted in the tool and connected to a vibrating part of the tool for converting vibrations of the tool into electrical energy.

1 . Device for generating electrical energy from vibrating tools, the device comprising piezoelectric means connected to at least a vibrating part of the tool for converting vibrations from the tool into electrical energy.  
   
   
       2 . The device of  claim 1 , wherein the piezoelectric means comprises at least one piezoelectric element subject to variable mechanical pressure, the at least one piezoelectric element being connected to a control circuit and to a stress restricting device for protecting the piezoelectric means.  
   
   
       3 . The device of  claim 2 , wherein the control circuit comprises at least one transformer, a rectifier and a tension regulator, for adjusting and/or regulating electrical parameters of the electrical energy.  
   
   
       4 . The device of  claim 3 , wherein the control circuit includes at least one electrical energy accumulator.  
   
   
       5 . The device of  claim 1 , wherein the tool is a well bore drilling tool and the piezoelectric means comprises at least one assembly of piezoelectric elements housed into a main tubular body having a first end connected to a stationary coupling device and a second end connected to a movable coupling device capable of axially moving in the main tubular body for applying varying pressure onto the at least one piezoelectric elements assembly, the at least one assembly of piezoelectric elements being connected to a control circuit for adjusting and/or regulating electrical parameters of the electrical energy.  
   
   
       6 . The device of  claim 5 , wherein the at least one assembly of piezoelectric elements comprises at least one an array of piezoelectric discs that are axially arranged and connected to a stress restricting device for preventing the array of discs from being affected by excessive stresses and impacts.  
   
   
       7 . The device of  claim 6 , wherein the at least one array of piezoelectric discs includes a first end and a second end, the first end having two electrical connecting terminals and at least one mechanical coupling bore, and the second end having two electrical connecting terminals and at least one mechanical coupling pin, with a first terminal of the first end being electrically connected to a first terminal of the second end and a second terminal of the first end being electrically connected to a second terminal of the second end.  
   
   
       8 . The device of  claim 7 , wherein the at least one array of piezoelectric discs comprises at least two axially connected arrays.  
   
   
       9 . The device of  claim 7 , wherein the array of piezoelectric discs is axially connected to an electrical adapting device forming part of the control circuit, the adapting device including at least one transformer and a diode bridge.  
   
   
       10 . The device of  claim 6 , wherein the array of piezoelectric discs receives pressure vibrations along an axis according to piezo coefficient g33 of the piezoelectric discs.  
   
   
       11 . The device of  claim 6 , wherein the array of piezoelectric discs receives pressure vibrations along two normal axes according to piezo coefficients g33 and g31 of the piezoelectric discs.  
   
   
       12 . The device of  claim 9 , wherein the stationary coupling device comprises an electric concentring device that houses a further part of the control circuit and at least one operation equipment.  
   
   
       13 . The device of  claim 12 , wherein the stationary coupling device, the electric concentring device, the movable coupling device and the main body include axially extending orifices for passing drilling mud employed in the drilling of the well bore.  
   
   
       14 . The device of  claim 8 , wherein the array of piezoelectric discs comprises an outer casing housing at least two piezoelectric discs arranged axially side by side, facing to each other by their disc faces, and mounted on an electrically insulating shaft, the discs being electrically in-parallel connected to the electrical connecting terminals.  
   
   
       15 . The device of  claim 14 , wherein the electrically insulating shaft has an end including an adjusting screw for compressing the array of piezoelectric discs.  
   
   
       16 . The device of  claim 5 , wherein the main tubular body has at least one notch arranged at the second end of the main tubular body, the movable coupling device at least partially and axially moving within the main tubular body and including a key radially outwardly extending through the at least one notch for restricting the axial relative movement between the main tubular body and the movable coupling device.  
   
   
       17 . The device of  claim 12 , wherein said part of the control circuit housed in the concentring device comprises at least one capacitor and a tension regulator.  
   
   
       18 . The device of  claim 17 , wherein the adapting device is a device for adapting the tension and impedance of the electrical energy and is connected said further part of the control circuit.  
   
   
       19 . The device of  claim 6 , wherein the stress restricting device is selected from the group consisting of springs, high impact resisting rubber, Belleville-type discs springs, hydraulic springs.  
   
   
       20 . The device of  claim 19 , wherein the stress restricting device has a stiffness that may be adjusted to reach the mechanical resonance of the electrical energy generating device.  
   
   
       21 . The device of  claim 1 , wherein the piezoelectric means are made of a material selected from the group consisting of ceramics, crystals, composite materials, lead titanate, lead zirconate.  
   
   
       22 . The device of  claim 5 , further comprising accumulator means for accumulating at least part of the electrical energy generated by the device.