Connection of a free-piston stirling machine and a load or prime mover permitting differing amplitudes of reciprocation
AssigneeSunPower Corporation
InventorWilliam T. Beale
Life of this patent
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Abstract
The reciprocatable power piston of a free-piston Stirling machine is drivingly linked to a reciprocatable component body of an associated apparatus by at least one spring with no rigid connection linking the piston to the component body. The spring drive linkage allows the power piston and the reciprocatable component body of the associated apparatus to reciprocate at different amplitudes of oscillation. Therefore, the Stirling machine and the associated apparatus can be optimized at different amplitudes of piston and the component body oscillation thereby improving the optimization of two very different dynamic systems that are drivingly connected together.
Claims13
An improved combination of a free-piston Stirling machine including a reciprocatable power piston drivingly linked to an associated apparatus having a reciprocatable component body that is part of a mechanical load that the Stirling machine drives or of a prime mover that drives the Stirling machine, wherein the improvement comprises:
- at least one spring connected to and drivingly linking the piston to the component body, there being no rigid connection linking the piston to the component body thereby permitting the piston and the component body to reciprocate at different amplitudes of oscillation.
A method for designing, fabricating and operating a combination of a free-piston Stirling machine including a reciprocatable power piston drivingly linked to an associated apparatus having a reciprocatable component body that is part of a mechanical load that the Stirling machine drives or is a part of a prime mover that drives the Stirling machine, wherein the method comprises:
- connecting and drivingly linking the piston to the component body by at least one spring with no rigid connection linking the piston to the component body, and designing the spring, the mass of the reciprocatable component body, the damping of the reciprocatable component body and the operating ratio of the component body amplitude of reciprocation to the power piston amplitude of reciprocation, when the combination is operated at the natural frequency ωn of oscillation of the component body, to have a relationship between them in accordance with
-
- X
- 2
- X
- 1
-
- =
- k
- s
-
- m
- 2
- c
- l
- wherein
- ks is the spring constant of the spring;
- m2 is the mass of the reciprocatable component body;
- cl is a damping constant for damping of the reciprocatable component body;
- X2 is the amplitude of reciprocation of the component body;
- X1 is the amplitude of reciprocation of the power piston;
- and
- ω
- n
- =
- k
- s
- m
- 2
- .
Dependencies are inferred from the claim text.