Abstract: The invention relates to a structure of a liquefied hydrogen pump, located within a liquefied hydrogen fuel tank of a hydrogen (gas ignited) engine, in which a cylinder holder is linked to a lower end of the connecting rod which is reciprocated upwardly and downwardly by means of an external driving source via a first universal joint and a cylinder is housed within a piston holding member via each arm of the cylinder holder so as to be enabled to move upwardly and downwardly. A stepped engagement recess is formed in a bottom end portion of a pump housing. A bottom lid of the piston holding member is linked to an engagement rod via a second universal joint, the engagement rod being received by the engagement recess so that a radial displacement of the piston holding member and piston member to the pump housing is permitted and an automatic axial alignment of both piston and cylinder to an axial line 01--01 of the pump housing is carried out.

Abstract: A gas-injection valve for injecting gaseous fuel into the combustion chamber of an internal combustion engine, comprising a valve housing and, disposed therein, a longitudinally displaceable piston having connected thereto a poppet valve for controlling an injection port, which poppet valve opens in the direction of gas flow, said piston separating a gas space from an operating space adapted to be pressurized by having hydraulic control fluid fed thereto by a pressure pump, and the gas pressure within the gas space alone being sufficient to move the poppet valve to and to hold it in its closed position when the operating space is depressurized.

Abstract: The method by this invention is characterized in that a fuel injection nozzle to inject diesel fuel oil into cylinder and an auxiliary injection nozzle to inject the combustible gas or non-combustible gas into the cylinder are provided, and that said combustible gas or non-combustible gas is injected in the latter stage of the diesel fuel oil combustion. More concretely, a part of the fuel is reformed to combustion gases by a fuel reforming apparatus and the gases are injected, or the combustible gas or non-combustible gas is prepared in another gas cylinder, and this gas is injected in the latter stage of the combustion.

Abstract: A vane pump provided with a center housing, front and rear housings holding the center housing therebetween, a rotor eccentrically disposed in the center housing and rotatably supported by the front and rear housings, a single vane diametrically movably inserted in the rotor, and a guide for regulating the projection of the vane out of the rotor. The guide comprises an axle provided centrally on each side of the vane, a circular hole formed in the inner surface of each of the front and rear housings and having a center positioned just in the middle between both centers of the rotor and the center housing, and a rolling bearing interposed between the axle and the circular hole to guide the axle in a circular path having a diameter equal to the eccentricity of the rotor. The center housing has an inner surface with a cross-sectional profile that is firstly drawn by the tip of the vane when the rotor turns and then expanded by a preselected clearance.

Abstract: An oil ring having an axially and radially thin cross-section and a single cylinder contacting face to bear against the cylinder wall with a pressure of 2 Kg/cm.sup.2 to 6 Kg/cm.sup.2. The oil ring is dimensioned to satisfy the following equations:0.01.ltoreq.B/D.ltoreq.0.025 (1)T/B.ltoreq.4 (2)0.1.ltoreq.t/B.ltoreq.0.5 (3)where B is the axial height of the oil ring; D is the outer diameter of the oil ring; T is the radial thickness of the oil ring; and t is the width of the cylinder contacting face.