A gas ejection apparatus ejects gas using a compressor that compresses the gas by a rotating body inside a cylinder, and includes a detector and a microcomputer. The detector detects a position of the rotating body inside the cylinder based on positions of gears which are coupled to the rotating body. When the microcomputer receives an ejection instruction, the microcomputer controls intake and exhaust of the compressor according to detection results of the detector, and causes the compressor to wait in an intake completion state upon completion of ejection of the gas that was performed in response to the ejection instruction.

The invention relates to a piston machine which comprises: a housing with a chamber with has a substantially circle sector-shaped cross-section; a pivotal piston which is designed as a pivoting element, is arranged in the housing and comprises a first working surface, wherein the housing and the piston define at least one first variable working chamber; a drive or output which is connected to the piston; and an outlet which is arranged in the working chamber for discharging a working fluid. The housing has a cooling opening in at least one housing wall, said opening leading to the chamber at least for convectively cooling a piston side opposite the first working surface by means of a coolant.

An air compressor according to an embodiment, which includes a cylinder and a rotating body provided to be rotatable around a rotation axis in the cylinder so as to generate compressed air through intake and exhaustion caused by rotation of the rotating body, includes an intake valve. The intake valve takes air in the intake and exhaustion. The intake valve is provided in the cylinder.

A rotation device according to an embodiment includes a first gear, a second gear, and an energizing part. The first gear includes a toothless part and is connected with a rotation driving source. The toothless part is obtained by cutting a part of continuous teeth of the first gear. The second gear is arranged to be able to be engaged with the first gear and is rotated, when engaged with the first gear, in a predetermined direction by a rotation of the rotation driving source in one direction. The energizing part energizes the second gear in a direction reverse to the predetermined direction when the second gear is in a free state in which an engagement of the second gear with the first gear is released by the toothless part.

An active gas regenerative refrigerator includes a plurality of compressor-expander units, each having a hermetic cylinder with a drive piston configured to be driven reciprocally therein, and a quantity of working fluid in each end of the cylinder. A piston seal in a central portion of the cylinder prevents passage of the working fluid between ends of the cylinder. Movement of the piston to a first extreme results in radial compression of one of the quantities of working fluid in a cylindrical gap formed between one end of the piston and an inner surface of the cylinder, while the other quantity is expanded in the opposite end of the cylinder. The piston includes a plurality of magnets arranged in pairs, with magnets of each pair positioned with like-poles facing each other. A piston drive is configured to couple with transverse magnetic flux regions formed by the magnets.

An active gas regenerative refrigerator includes a plurality of compressor-expander units, each having a hermetic cylinder with a drive piston configured to be driven reciprocally therein, and a quantity of working fluid in each end of the cylinder. A piston seal in a central portion of the cylinder prevents passage of the working fluid between ends of the cylinder. Movement of the piston to a first extreme results in radial compression of one of the quantities of working fluid in a cylindrical gap formed between one end of the piston and an inner surface of the cylinder, while the other quantity is expanded in the opposite end of the cylinder. The piston includes a plurality of magnets arranged in pairs, with magnets of each pair positioned with like-poles facing each other. A piston drive is configured to couple with transverse magnetic flux regions formed by the magnets.

The invention relates to a piston machine which comprises: a housing with a chamber with has a substantially circle sector-shaped cross-section; a pivotal piston which is designed as a pivoting element, is arranged in the housing and comprises a first working surface, wherein the housing and the piston define at least one first variable working chamber; a drive or output which is connected to the piston; and an outlet which is arranged in the working chamber for discharging a working fluid. The housing has a cooling opening in at least one housing wall, said opening leading to the chamber at least for convectively cooling a piston side opposite the first working surface by means of a coolant.