Claims
- 1. A power control for a heat engine having an engine block defining therein a cylinder, a piston received within said cylinder in which working gas can expand at the high cycle temperature to produce a power stroke of said piston, and in which said piston can compress working gas at the low cycle temperature in a compression volume, said power control comprising:
- a control member disposed in said engine block and movable axially with respect to both said piston and said engine block, wherein said control member is cylindrical and coaxially disposed with respect to said piston, and includes means in said control member defining a cylindrical bore therethrough, said bore receiving structure attached to said piston;
- means defining a gas passage that is positioned to communicate at one end thereof with said compression volume at some positions of said control member and said piston, and to be closed by movement of said piston relative to said control member at other positions of said control member and said piston, wherein said gas passage means is closed at a certain position of said piston stroke by movement of said piston that reduces said compression volume, said certain position being adjustable by adjustment of the position of said control member relative to said engine block;
- an enclosed gas volume communicating with said gas passage means at the other end thereof;
- a translation mechanism for moving said control member relative to said engine block kinematically independent of the movement of said piston for adjusting the position in said piston stroke when said communication between said gas passage means and said compression volume is closed, whereby the effective volume of said compression volume, and hence the engine power, can be controlled.
- 2. The power control defined in claim 1, wherein said control member is a sleeve having an externally threaded portion threadedly engaged with an internally threaded portion of said cylinder, and said translation mechanism includes means for rotating said sleeve relative to said cylinder to cause said sleeve to translate axially as said threaded portions rotate relatively.
- 3. The power control defined in claim 2, wherein said rotating means includes a threaded control rod extending transversely of the axis of said cylinder, and a gear non-rotatably attached to said sleeve and threadly engaged with said control rod, whereby movement of said control rod causes said gear and said sleeve to rotate.
- 4. The power control defined in claim 3, wherein said gear teeth are axially elongated whereby said gear engages said control rod at all axial positions of said sleeve throughout its full range of operation.
- 5. The power control defined in claim 1, wherein said control member includes a sleeve coaxially mounted for axial translation in said cylinder; said gas passage means includes ports in said sleeve, and a manifold in said cylinder communicating with said ports at all axial positions of said sleeve; said piston oscillates relative to said control member and closes said ports at selected positions in the piston travel.
- 6. The power control defined in claim 1, further comprising a piston rod attached to said piston and extending through said bore in said control member, said gas passage means including a section of said piston rod which is relieved to permit gas to flow therealong between said bore and said piston rod to an opening leading to said enclosed gas volume, said control member being axially movable to control the position on the stroke of said piston rod at which said relieved section of said piston rod is covered by said control member to thereby control the effective volume of said compression space volume.
- 7. In a Stirling engine, including at least one cylinder, gas acting means in said cylinder reciprocally mounted for oscillation between an expansion space and a compression space for cyclically circulating a working gas contained within said cylinder through a heater, a regenerator and a cooler to create a pressure wave, and for moving under the influence of said pressure wave to produce output power, and for moving in said cylinder to compress the working gas; wherein the improvement resides in a power control device; comprising:
- an annular sleeve slidably disposed for axial movement in said cylinder to selected positions relative to the lowermost position of said gas acting means;
- a port extending through said sleeve for establishing communication between said compression space and a chamber adapted to be pressurized to the engine working gas charge pressure;
- a translation mechanism for moving said sleeve to selected axial positions in said cylinder kinematically independent of the oscillating position of said gas acting means so as to adjust the axial position of said sleeve port;
- whereby the commencement of the compression phase of the Stirling cycle can be controlled by the position of said ports, and the magnitude of said pressure wave and therefore the engine power, can thereby be controlled.
- 8. The device defined in claim 7, wherein said translation mechanism includes an externally threaded section on said sleeve and an internally threaded section in said cylinder, whereby rotation of said sleeve about its axis will cause axial translation of said sleeve.
- 9. The device defined in claim 8, wherein said translation mechanism further includes a set of axially elongated, angularly spaced teeth formed on said sleeve, and an elongated control rod having teeth engaged with said set of teeth on said sleeve whereby movement of said control rod causes rotation of said sleeve about its axis.
- 10. The device defined in claim 7, wherein said sleeve includes a second set of ports extending therethrough and communicating between said compression space and said cooler.
- 11. The device defined in claim 7, wherein said gas-acting means includes a power piston, a piston rod connected to said power piston and linked to a reciprocating-to-rotating motion conversion apparatus; a rod seal is disposed around said piston rod and contained in a seal block for preventing leakage of working gas out of said cylinder; said sleeve engages said seal block for movement therewith, and said translation mechanism moves said seal block.
- 12. The device defined in claim 11, wherein said translation mechanism includes an externally threaded section on said seal block and an internally threaded section in said cylinder, whereby rotation of said seal block about its axis will cause axial translation of said seal block and said sleeve.
- 13. The device defined in claim 12, wherein said translation mechanism further includes a set of axially elongated, angularly spaced teeth formed on said seal block and an elongated control rod having teeth engaged with said set of teeth on said seal block whereby movement of said control rod causes rotation of said seal block about its axis.
- 14. The device defined in claim 7, further comprising: an annular manifold around said cylinder of such axial width that communication is established between said sleeve port and said manifold at all axial positions of said sleeve, and a gas conduit communication between said manifold and said chamber.
- 15. The device defined in claim 7, wherein said chamber is a crankcase of said engine, and further comprising means for preventing oil from entering said sleeve from said crankcase.
Parent Case Info
This application is a continuation of application Ser. No. 232,165, filed Feb. 6, 1981, abandoned.
Government Interests
The government of the United States of America has rights in this invention pursuant to Contract No. DEN3-32 awarded by the Department of Energy.
US Referenced Citations (4)
Continuations (1)
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Number |
Date |
Country |
Parent |
232165 |
Feb 1981 |
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