A method is provided for designing and producing fiber-reinforced polymer (FRP) pistons. Pistons made with FRP have a lower mass than prior art metal pistons conferring advantageous engine efficiency and stability. FRP pistons also increase the thermal efficiency of engines by having a lower thermal conductivity, with tighter piston-to-bore clearance, and/increased air-fuel ratio than pistons of metal. The technical parameters of the piston are identified, and a piston body blank is produced. The blank is then machined, a bearing surface for the pin bore is created, the piston blank is optionally coated, is optionally subjected to Heavy Metal Ion Implantation (HMII) treatment and is subjected to sodium silicate impregnation to produce the final pistons.

In a rotary direct-drive single-stage or multi-stage centrifugal pump (1) for cryogenic liquids, having a pump housing (2) for the pump (1) and an electric drive motor unit (12) in a motor housing (10) serving as a pump drive, wherein a shaft (11) of the drive motor unit (12) is mounted on two roller bearings (20; 21), and wherein at least one roller bearing (20; 21) is an unlubricated roller bearing, the structural design of the centrifugal pump (1) should be kept as simple as possible. This is achieved in that at least a first communicating connection, in particular a direct connecting channel (16), is configured between the pressure side (D) in the pump housing (2) and the roller bearing (21) on the pump housing side for a diverted part (F.sub.A1) of the main conveying flow (F.sub.H) of the cryogenic pumped medium to the roller bearing (21), and that a second communicating connection is configured between the roller bearing (21) on the pump housing side and the suction side (S) for the diverted part (F.sub.A2) of the cryogenic pumped medium back to the suction side (S) in the main conveying flow (F.sub.H) of the cryogenic pumped medium, so that a circulation of the diverted part (F.sub.A1, F.sub.A2) of the cryogenic pumped medium is ensured between the pressure side (D) in the pump housing (2) and only the roller bearing (21) on the pump housing side.

A method is provided for designing and producing fiber-reinforced polymer (FRP) pistons. Pistons made with FRP have a lower mass than prior art metal pistons conferring advantageous engine efficiency and stability. FRP pistons also increase the thermal efficiency of engines by having a lower thermal conductivity, with tighter piston-to-bore clearance, and/increased air-fuel ratio than pistons of metal. The technical parameters of the piston are identified, and a piston body blank is produced. The blank is then machined, a bearing surface for the pin bore is created, the piston blank is optionally coated, is optionally subjected to Heavy Metal Ion Implantation (HMII) treatment and is subjected to sodium silicate impregnation to produce the final pistons.

In a rotary direct-drive single-stage or multi-stage centrifugal pump (1) for cryogenic liquids, having a pump housing (2) for the pump (1) and an electric drive motor unit (12) in a motor housing (10) serving as a pump drive, wherein a shaft (11) of the drive motor unit (12) is mounted on two roller bearings (20; 21), and wherein at least one roller bearing (20; 21) is an unlubricated roller bearing, the structural design of the centrifugal pump (1) should be kept as simple as possible. This is achieved in that at least a first communicating connection, in particular a direct connecting channel (16), is configured between the pressure side (D) in the pump housing (2) and the roller bearing (21) on the pump housing side for a diverted part (F.sub.A1) of the main conveying flow (F.sub.H) of the cryogenic pumped medium to the roller bearing (21), and that a second communicating connection is configured between the roller bearing (21) on the pump housing side and the suction side (S) for the diverted part (F.sub.A2) of the cryogenic pumped medium back to the suction side (S) in the main conveying flow (F.sub.H) of the cryogenic pumped medium, so that a circulation of the diverted part (F.sub.A1, F.sub.A2) of the cryogenic pumped medium is ensured between the pressure side (D) in the pump housing (2) and only the roller bearing (21) on the pump housing side.

A housing assembly for a rotary engine, has: a rotor housing extending around an axis, the rotor housing having an inner face facing a rotor cavity; side housings secured to opposite sides of the rotor housing, the rotor cavity bounded axially between the side housings; and a seal received within a groove at an interface between the rotor housing and a first side housing, the groove annularly extending around the axis, located outwardly of the inner face, and overlapping a peripheral section of the first side housing, the seal having: an elastomeric member compressed between the peripheral section and the rotor housing; and a shield disposed inwardly of the elastomeric member, the shield having a melting point above a temperature of combustion gases, the shield in contact with both of the peripheral section of the first side housing and the rotor housing.

An internal combustion engine includes a combustion chamber, a fuel injector injecting fuel into the combustion chamber, a cylinder, a piston having a crown and reciprocating in the cylinder, the crown being exposed to the combustion chamber, and an ignition delay enhancer prolonging an ignition delay of a fuel-air mixture in the combustion chamber. A ceramic member is disposed on at least a fuel injection port, to which fuel is injected from the fuel injector, of the crown of the piston.

A rotary compressor includes: a vertically-positioned airtight compressor housing having an upper section including a discharge portion of a refrigerant, and a lower section including an inlet unit of the refrigerant and storing lubricant oil; a compressing unit, disposed in the lower section, compressing the refrigerant sucked in via the inlet unit and discharging the refrigerant from the discharge portion; a motor, disposed in the upper section, driving the compressing unit via a rotation shaft; and an accumulator attached to the compressor housing and connected to the inlet unit. Inside the accumulator and/or the compressor housing, silicon dioxide having a crystal structure containing a vacancy with a diameter equal to or less than a diameter of a water molecule or a composite including silicon dioxide having a crystal structure containing a vacancy with a diameter equal to or less than that of the water molecule is placed.

In a spark ignition engine, a thermal insulation thin layer is formed over a wall surface, facing an inside of a combustion chamber, of a base material forming the combustion chamber, and for a thermal conductivity [W/(m.Math.K)], a thermal diffusivity [mm.sup.2/s], and a thickness L [m] of the thermal insulation thin layer, L16.7 and L207.4().sup.0.5 are satisfied. With such a configuration, a heat loss Q_total escaping from gas in a cylinder to the wall of the combustion chamber over all strokes can be reduced, and the thermal efficiency can be improved without inducing degradation of knocking due to an increase in an amount of heating Q_intake of the gas in the cylinder during an intake stroke.

A housing assembly for a rotary engine, has: a rotor housing extending around an axis, the rotor housing having an inner face facing a rotor cavity; side housings secured to opposite sides of the rotor housing, the rotor cavity bounded axially between the side housings; and a seal received within a groove at an interface between the rotor housing and a first side housing, the groove annularly extending around the axis, located outwardly of the inner face, and overlapping a peripheral section of the first side housing, the seal having: an elastomeric member compressed between the peripheral section and the rotor housing; and a shield disposed inwardly of the elastomeric member, the shield having a melting point above a temperature of combustion gases, the shield in contact with both of the peripheral section of the first side housing and the rotor housing.