Patent ID: 7000389

Claim:
An engine for converting thermal energy to stored energy, the engine including: (a) a thermal energy converter including an expansion chamber which is adapted to vary in volume by the movement of a movable wall forming one part of said expansion chamber, said expansion chamber capable of performing an expansion-contraction cycle; (b) a working fluid in said expansion chamber which expands upon being heated whereby to displace the movable wall in a first direction to expand the volume of said expansion chamber and contracts upon being cooled to displace the movable wall in an opposed direction to reduce the volume of said expansion chamber; (c) a temperature modifier adapted to draw on: (i) a heat source to heat the working fluid to expand the volume of the expansion chamber by the displacement of the expansion wall to increase the volume of said expansion chamber as a first expansion part of said cycle; and (ii) a cooling source to cool the working fluid to reduce the volume of the expansion chamber and to permit the return of the movable wall as a second part of said cycle; and (d) pressure storage means operatively associated with said movable wall and adapted to deliver pressurised fluid to an accumulator means, said accumulator means for storing said pressurised fluid at an elevated pressure, wherein said accumulator means is capable of being bled of said pressurised fluid at a predetermined rate such that the accumulated said elevated pressure is maintained at a minimum threshold level, irrespective of the irregularity of the movement of said movable wall.