Preventing overstroke of free-piston stirling engine from loss of load
AssigneeSunPower Corporation
InventorJames Gary Wood
Life of this patent
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Abstract
A method for limiting the amplitude of reciprocation of a piston reciprocating in a cylinder of a free-piston Stirling engine. The method is the combination of both at least partially covering the heat rejecter cylinder port by the piston sidewall during a peak part of the inward reciprocation of the piston and at least partially covering the heat rejecter cylinder port by the displacer sidewall during a peak part of the outward reciprocation of the displacer. The piston and the displacer, at times during their reciprocation, fully cover the effective heat rejecter cylinder port when the piston amplitude of reciprocation is large and approaches the physical limit of the amplitude of reciprocation in order to avoid internal collisions by a reciprocating component.
Claims13
A method for limiting the amplitude of reciprocation of a piston reciprocating in a cylinder of a free-piston Stirling engine, the piston having a sidewall interfacing the cylinder and the piston sidewall having a circumferentially continuous end part at an inward end, the engine also including a displacer reciprocating in the cylinder and having a circumferentially continuous end part of the displacer sidewall at a displacer outward end, the engine further including a compression space interposed between the piston and the displacer and a heat rejecter cylinder port through the engine cylinder and opening into the compression space, wherein the method comprises:
- (a) at least partially covering the heat rejecter cylinder port by the circumferentially continuous end part of the piston sidewall during a peak of the inward reciprocation of the piston;
- and
- (b) at least partially covering the heat rejecter cylinder port by the circumferentially continuous end part of the displacer sidewall during a peak of the outward reciprocation of the displacer.
Dependencies are inferred from the claim text.