Buoyancy control system

Abstract

The present invention relates to a buoyancy control system, and in particular to a buoyancy control system for controlling the buoyancy of an underwater submersible. The buoyancy control system comprises a buoyancy chamber ( 5 ) having a seawater inlet ( 5 A) and a seawater outlet ( 11 A), a power supply( 31 ) used to power at least one electrical component of the system, and a hydraulic system for pumping seawater from the chamber through the outlet. The hydraulic system comprises a hydraulic pump ( 28 ) and a pressure multiplier ( 34 ), the hydraulic pump for applying pressure to the pressure multiplier, and the pressure multiplier for increasing the pressure applied thereto by the hydraulic pump, and for applying the increased pressure to seawater from the chamber to thereby pump out the seawater.

1 . A buoyancy control system for controlling the buoyancy of an underwater submersible, the system comprising: 
 a buoyancy chamber having a seawater inlet and a seawater outlet;    a power supply used to power at least one electrical component of the system; and    a hydraulic system for pumping seawater from the chamber through the outlet, the hydraulic system comprising a hydraulic pump and a pressure multiplier, the hydraulic pump for applying pressure to the pressure multiplier, and the pressure multiplier for increasing the pressure applied thereto by the hydraulic pump, and for applying the increased pressure to seawater from the chamber to thereby pump out the seawater.    
   
   
       2 . A system according to  claim 1  further comprising regenerative means whereby the flow of seawater passing into said inlet is converted into electrical energy for re-charging a power supply.  
   
   
       3 . A system according to  claim 2  wherein the regenerative means is configured to operate when the system is utilised to cause the vehicle to descend.  
   
   
       4 . A system according to  claim 2  wherein said regenerative means includes a turbine, driven by the flow of seawater, to provide an electrical output.  
   
   
       5 . A system according to  claim 4  wherein said electrical output is processed locally by a receiver circuit configured to produce a smoothed electrical signal for application to a charging circuit.  
   
   
       6 . A system according to  claim 5  wherein said charging circuit is controlled by an electronic control system to distribute charging current to the battery.  
   
   
       7 . A system according to  claim 2  wherein said regenerative means is dynamically adjusted according to the pressure differential there across during said flow of seawater.  
   
   
       8 . A system according to  claim 1  wherein the buoyancy chamber comprises a glass, steel or titanium sphere.  
   
   
       9 . A system according to  claim 1  wherein the buoyancy chamber can withstand pressures at undersea depths of 3000 m or greater, and has a capacity to hold up to 34 kg of seawater.  
   
   
       10 . A system according to  claim 1  wherein the pressure multiplier comprises input and output surfaces in pressure transmitting relation, the output surface having a surface area less than the surface area of the input surface, the pressure increase generated by the pressure multiplier being determined by the ratio of surface areas of the input and output surfaces.  
   
   
       11 . A system according to  claim 10  wherein the input surface comprises a plate.  
   
   
       12 . A system according to  claim 10  wherein the output surface comprises a plunger or piston.  
   
   
       13 . A system according to  claim 12  wherein the pressure multiplier includes an output and comprises a non-return valve or valves associated therewith.  
   
   
       14 . A system according to  claim 1  further comprising: 
 a flexible bag provided internally of the buoyancy chamber; and    expanding means for causing expansion of said flexible bag.    
   
   
       15 . A system according to  claim 14  wherein said expanding means comprises a pressurised container for providing gas to the flexible bag.  
   
   
       16 . A system according to  claim 15  wherein a volume of the pressurised container and the pressure of the gas therein are selected according to a mission profile of a submersible vehicle, the system of which forms a part.  
   
   
       17 . A system according to  claim 1  further comprising an electronic control system having means for transmitting data concerning the state of operation of the system to a home station.  
   
   
       18 . A submersible vehicle including a buoyancy control system according to  claim 1.