A multi-stage Stirling cycle machine and a steady-state operating parameter control method therefor are disclosed. In the Stirling cycle machine, a mechanical energy input piston, a mechanical energy transfer double-acting free piston, and a mechanical energy output piston constitute a plurality of Stirling working units which are arranged in stages. The mechanical energy input piston is connected to a mechanical energy input apparatus. The mechanical energy output piston is connected to a mechanical energy output apparatus. When the Stirling cycle machine is used as an engine, a relatively small amount of mechanical energy is input into a mechanical energy input piston in a set of pistons, the mechanical energy is amplified by a multi-stage Stirling unit, and a relatively large amount of mechanical energy is then output by a mechanical energy output piston.

According to an embodiment of a hot air engine, the hot air engine includes a transmission with a connecting rod and a double-acting step piston. The double-acting step piston has a first section with a larger diameter and a second section with a smaller diameter, and is arranged in a cylinder. The double-acting step piston is at least partially hollow and the connecting rod extends through the second section and is articulatedly connected in the first section of the double-acting step piston. The double-acting step piston has sealing rings both in the first section and in the second section.

A Stirling engine comprising: a crank case (1) with a crank shaft (2) arranged therein, a displacer cylinder (3) with a reciprocatingly arranged displacer piston (4) therein, said displacer piston (4) being connected to said crank shaft (2) via a connecting rod (5) extending through a first end of said displacer cylinder (3), and wherein the displacer cylinder (3) defines a hot chamber (6) and a cool chamber (7) separated by the displacer piston (4), a working cylinder (8) defining a working cylinder chamber (11) with a reciprocatingly arranged working piston (9) therein, said working piston (9) being connected to said crank shaft (2) via a connecting rod (10) extending through a first end of the working cylinder (8), a heater device (14), arranged at a second end of said displacer cylinder (3) opposite to said first end and configured to heat a working gas which is present in the hot chamber (6) of the displacer cylinder (3) and in fluid communication with the working cylinder chamber (11) through a working gas channel which comprises a first heat exchanger (16) extending from a cylinder head (19) of the displacer cylinder (3) into the heater device (14), a second heat exchanger (17) formed by a regenerator arranged outside the heater device (14), and a transition flow element (22) provided between said second heat exchanger (17) and the working cylinder (8), wherein the Stirling engine also comprises a cooling system for cooling of the displacer cylinder, the working cylinder and the tubular transition flow element. The Stirling engine comprises a first outer tube (30) arranged outside and enclosing the working cylinder (8), and the cooling system comprises a first channel (31) configured to receive a cooling fluid and defined by the outer periphery of the working cylinder (8) and the inner periphery of said first outer tube (30), and said channel (31) covers at least 50% of the outer peripheral surface of the working cylinder (8).

An alpha type Stirling engine (1) comprises an expansion cylinder (2) and a compression cylinder (3), a regenerator (4), a cooler (5), and a heater (6). Each one of the expansion cylinder (2) and the compression cylinder (3) has a movable piston (10, 11) connected to a respective linear electric generator/motor (8, 9), wherein the Stirling engine (1) further comprises a control unit (20) which is operatively connected to the linear electric generators/motors (8, 9) and which is configured to control the linear electric generators/motors (8, 9) individually so as to enable a different stroke length and/or motion profile of the piston (10) in the expansion cylinder (2) compared to the piston (11) in the compression cylinder (3).

A Stirling engine comprising: a crank case (1) with a crank shaft (2) arranged therein, a displacer cylinder (3) with a reciprocatingly arranged displacer piston (4) therein, said displacer piston (4) being connected to said crank shaft (2) via a connecting rod (5) extending through a first end of said displacer cylinder (3), and wherein the displacer cylinder (3) defines a hot chamber (6) and a cool chamber (7) separated by the displacer piston (4), a working cylinder (8) defining a working cylinder chamber (11) with a reciprocatingly arranged working piston (9) therein, said working piston (9) being connected to said crank shaft (2) via a connecting rod (10) extending through a first end of the working cylinder (8), a heater device (14), arranged at a second end of said displacer cylinder opposite to said first end and configured to heat a working gas which is present in the hot chamber (6) of the displacer cylinder (3) and in fluid communication with the working cylinder chamber (11) through a working gas channel which comprises a first heat exchanger (16) extending from a head (19) of the displacer cylinder (3) into the heater device (14), a second heat exchanger (17) formed by a regenerator arranged outside the heater device (14), and a third heat exchanger (20) formed by a cooler arranged between the regenerator (17) and the working cylinder chamber (11). At any point along the working gas channel, as seen cross wise to an assumed working gas flow direction through the working gas channel, the cross section area of the working gas channel defined by the first, second and third heat exchangers is within the range of the medium cross section area of the working gas channel +/10%.

A Stirling engine comprising: a crank case (1) with a crank shaft (2) arranged therein, a displacer cylinder (3) with a reciprocatingly arranged displacer piston (4) therein, said displacer piston (4) being connected to said crank shaft (2) via a connecting rod (5) extending through a first end of said displacer cylinder (3), and wherein the displacer cylinder (3) defines a hot chamber (6) and a cool chamber (7) separated by the displacer piston (4), a working cylinder (8) defining a working cylinder chamber (11) with a reciprocatingly arranged working piston (9) therein, said working piston (9) being connected to said crank shaft (2) via a connecting rod (10) extending through a first end of the working cylinder (8), a heater device (14), arranged at a second end of said displacer cylinder (3) opposite to said first end and configured to heat a working gas which is present in the hot chamber (6) of the displacer cylinder (3) and in fluid communication with the working cylinder chamber (11) through a working gas channel which comprises a first heat exchanger (16) extending from a cylinder head (19) of the displacer cylinder (3) into the heater device (14), a second heat exchanger (17) formed by a regenerator arranged outside the heater device (14), and a transition flow element (22) provided between said second heat exchanger (17) and the working cylinder (8), wherein the Stirling engine also comprises a cooling system for cooling of the displacer cylinder, the working cylinder and the tubular transition flow element. The Stirling engine comprises a first outer tube (30) arranged outside and enclosing the working cylinder (8), and the cooling system comprises a first channel (31) configured to receive a cooling fluid and defined by the outer periphery of the working cylinder (8) and the inner periphery of said first outer tube (30), and said channel (31) covers at least 50% of the outer peripheral surface of the working cylinder (8).

A Stirling engine is described which, in accordance with a first exemplary embodiment, has a transmission with a connecting rod and a double-acting step piston which is arranged in a cylinder. The step piston has a first section with a greater diameter and a second section with a smaller diameter, and is at least partially hollow. The connecting rod runs on the inside through the second section, and is connected in an articulated manner in the first section of the step piston.

An engine comprising: a sealed and rigid case containing a liquid and a work mixture of gas and steam from the liquid, a heat source able to heat the liquid, a cold source able to cool the work mixture, a movable device positioned within the case, which can move between a first position where the movable device minimize the contact between the work mixture and the cold source, and maximize the contact between the liquid and the work mixture, and a second position where the movable device maximize the contact between the work mixture and the cold source, and minimize the contact between the liquid and the work mixture, an actuator able to move the movable device from the first position to the second position and vice versa.

The invention relates to a heat cycle machine which operates according to the Stirling cycle and can be used as a multi-valent stand-alone power supply for households (electricity and heat), that is to say using various energy sources (sunlight, combustion of present materials). The heat cycle machine comprises at least one hot oil connection (4, 5) that can be connected to any desired heat source, at least one cold water connection (6, 7) and two chambers (2) that contain a working gas. The chambers (2) are connected to one another via at least one working gas line (18, 20) in which is integrated a working rotor (13) that can be driven by the working gas which is alternately heated in one of the chambers (2) and cooled in the other chamber (2).

An integrated wind and solar solution is provided, including a solar energy collection assembly (100) and a vertical axis wind turbine (400), combined to provide an integrated power output. In preferred embodiments, the vertical axis wind turbine is positioned above the solar energy collection assembly. Concentrating solar mirror collectors (116) are used to direct sunlight to a heat engine (250), which converts the collected heat energy into rotary motion. Rotary motion from the heat engine and from the vertical axis wind turbine preferably are on the same rotating axis (600), to facilitate load sharing between these two sources. A dual axis azimuth-altitude solar panel alignment tracking system is used in order to boost the energy conversion capability of the solar energy collectors.