There is provided a free rotary fluid machine including: a main body which is provided in a hollow cylindrical shape, and has an elliptical inner circumferential surface; a rotor which is provided in the main body, and rotates about the same rotation center as the main body; tip seals which are provided at one side of the rotor so as to be in contact with the inner circumferential surface of the main body; and blades which are provided between the tip seals provided adjacent to each other, and supported by the tip seals, in which the blade has one end surface that faces the inner circumferential surface of the main body, and the other end surface that is opposite to one end surface, and centers of radii of curvature of one end surface and the other end surface are positioned at the same side. As described above, a space formed among the inner circumferential surface of the main body, the rotor, and the tip seal is sealed by the auxiliary tip seal, and as a result, it is possible to reduce friction between the tip seal and the main body and to prevent a leak of an introduced working fluid.

An optimized mechanical expander or fluid expansion device with a delayed opening timing is disclosed. In the optimized design, rotors in the expander alternatingly rotate sequentially through an intake position in which the transport volume is open to the housing inlet, a closed position in which the transport volume is closed to the housing outlet, and a discharge position in which the transport volume is open to the housing outlet. During rotation, a first opening forms between the housing and each rotor. After further rotation, a second opening is formed that is located between the first opening and a back end of the rotor. In one aspect, the mechanical expander has an opening profile including an initial opening phase in which the opening between the rotor and outlet forms at a lesser rate than during a subsequent secondary opening phase.

An optimized mechanical expander or fluid expansion device with a delayed opening timing is disclosed. In the optimized design, rotors in the expander alternatingly rotate sequentially through an intake position in which the transport volume is open to the housing inlet, a closed position in which the transport volume is closed to the housing outlet, and a discharge position in which the transport volume is open to the housing outlet. During rotation, a first opening forms between the housing and each rotor. After further rotation, a second opening is formed that is located between the first opening and a back end of the rotor. In one aspect, the mechanical expander has an opening profile including an initial opening phase in which the opening between the rotor and outlet forms at a lesser rate than during a subsequent secondary opening phase.

A reversible pneumatic vane motor includes a stator housing with a pressure air inlet passage and an exhaust air outlet passage, a cylinder supported in the stator housing, a vane carrying rotor rotatable in the cylinder and forming a clearance seal portion with the cylinder, air communication ports located at opposite sides of the seal portion for supplying motive pressure air or scavenging exhaust air from the cylinder, a primary outlet diametrically opposite the clearance seal portion, and a directional valve for connecting alternatively the air communication ports to the pressure air inlet passage and the exhaust air outlet passage. The motor also includes auxiliary outlet ports which are located between the primary outlet and each one of the air communication ports, and the directional valve includes control parts for opening up and closing, respectively, communication between the auxiliary outlet ports and the atmosphere via the exhaust air outlet passage.

A rotary internal combustion engine includes an arcuate compression chamber, an arcuate expansion chamber, an output shaft, and a piston coupled to the output shaft for movement through the arcuate compression chamber and the arcuate expansion chamber. The piston has a leading end, a trailing end, an inlet valve that is located at the leading end of the piston for receiving a compressible fluid from the compression chamber and an outlet valve that is located at the trailing end of the piston for expelling a combustion gas into the arcuate expansion chamber.

A rotary internal combustion engine includes an arcuate compression chamber, an arcuate expansion chamber, an output shaft, and a piston coupled to the output shaft for movement through the arcuate compression chamber and the arcuate expansion chamber. The piston has a leading end, a trailing end, an inlet valve that is located at the leading end of the piston for receiving a compressible fluid from the compression chamber and an outlet valve that is located at the trailing end of the piston for expelling a combustion gas into the arcuate expansion chamber.

An internal combustion engine includes a housing defining an internal cavity, an inner body sealingly moving within the internal cavity for defining at least one combustion chamber of variable volume, a pilot subchamber in communication with the at least one working chamber, an ignition element in communication with the pilot subchamber, a main injector communicating with the at least one combustion chamber, and a pilot injector having a tip in communication with the pilot subchamber. The tip of the pilot injector includes at least a first injection hole defining a first spray direction and a second injection hole defining a second spray direction different from the first spray direction. The first spray direction extends toward the communication between the pilot subchamber and the at least one working chamber. A method of performing combustion in an internal combustion engine is also discussed.

A scroll compressor includes a discharge guide disposed in a high-pressure part to guide refrigerant discharged from a compression part to a refrigerant discharge pipe, and the discharge guide may extend by a preset height from an inner circumferential surface of a casing constituting the high-pressure part toward one side surface of a high and low pressure separation plate. This can guide discharge refrigerant discharged to the high-pressure part to quickly flow to the refrigerant discharge pipe before being spread in an entire space of the high-pressure part, thereby preventing the high and low pressure separation plate from being overheated by discharge refrigerant of high temperature. This can result in preventing suction refrigerant of a low-pressure part from being heated by heat of discharge refrigerant transferred through the high and low pressure separation plate, thereby reducing a specific volume of the suction refrigerant and improving compressor efficiency.

A rotary internal combustion engine including a rotor assembly where at least a first and a second of the combustion chambers have unequal theoretical volumetric ratios. Also, a rotary internal combustion engine including first and second rotor assemblies where at least one of the combustion chambers of the first rotor assembly and at least one of the combustion chambers of the second rotor assembly have unequal effective volumetric compression ratios and/or unequal effective volumetric expansion ratios.

A rotary internal combustion engine including a rotor assembly where at least a first and a second of the combustion chambers have unequal theoretical volumetric ratios. Also, a rotary internal combustion engine including first and second rotor assemblies where at least one of the combustion chambers of the first rotor assembly and at least one of the combustion chambers of the second rotor assembly have unequal effective volumetric compression ratios and/or unequal effective volumetric expansion ratios.