Abstract: A method for manufacturing a supercharger rotor by casting a profile portion of a supercharger rotor and a shaft penetrating the same, having the steps of: first cutting a left and right helical cross portion on a surface of the shaft connected to the profile portion, wherein the cross portion includes a right handed helical groove and a left handed helical groove, and these grooves cross each other; and casting the profile portion around the shaft in die-casting. In this way, a plurality of profile portion divided metal molds surround a profile portion and end metal molds surround both rotor ends. A helical core is attached to one end mold to pass through the profile portion. A rotor-shaped cavity forms inside the molds. Hot metal is pressurized, injected and solidified in the cavity, and the end mold having the helical core is pulled out by rotation along a helical line.

Abstract: A plurality of profile portion divided metal molds 12 surround a profile portion 11a of a supercharger rotor 11 to allow division. A pair of end metal molds 14 and 15 surround both ends of the rotor. A helical core 16 is attached to one end metal mold 14 so as to be helically passed through the profile portion of the rotor. A rotor-shaped cavity 13 is formed inside by the profile portion divided metal molds, and the end metal molds. Hot metal is pressurized, and injected and solidified in the cavity. Then, the end metal mold 14 having the helical core is pulled out by being rotated along a helical line.

Abstract: A plurality of profile portion divided metal molds 12 surround a profile portion 11a of a supercharger rotor 11 to allow division. A pair of end metal molds 14 and 15 surround both ends of the rotor. A helical core 16 is attached to one end metal mold 14 so as to be helically passed through the profile portion of the rotor. A rotor-shaped cavity 13 is formed inside by the profile portion divided metal molds, and the end metal molds. Hot metal is pressurized, and injected and solidified in the cavity. Then, the end metal mold 14 having the helical core is pulled out by being rotated along a helical line.

Abstract: A plurality of profile portion divided metal molds 12 surround a profile portion 11a of a supercharger rotor 11 to allow division. A pair of end metal molds 14 and 15 surround both ends of the rotor. A helical core 16 is attached to one end metal mold 14 so as to be helically passed through the profile portion of the rotor. A rotor-shaped cavity 13 is formed inside by the profile portion divided metal molds, and the end metal molds. Hot metal is pressurized, and injected and solidified in the cavity. Then, the end metal mold 14 having the helical core is pulled out by being rotated along a helical line.

Abstract: An air supply device for a fuel cell is disclosed which is provided with a displacement compressor (10) for supplying pressurized air as an air source to a cathode through an air supply line connected to the cathode inlet side of the fuel cell (I) so that a burned gas obtained by burning an anode exhaust gas (AG) discharged from an anode of the fuel cell may be conducted to the intake side of an exhaust gas turbine (8) for driving the displacement compressor, and so that air may be supplied to the cathode (2) by driving the displacement compressor (10) with the exhaust gas turbine that operates with the burned gas of the anode exhaust gas. A heat exchanger (22) vaporizes fuel fed to the anode of the fuel cell. The heat exchanger takes in exhaust gas from the turbine and outputs a high temperature exhaust gas, which is conducted to the intake of the turbine.

Abstract: A supercharger arrangement for a vehicle engine equipped with a screw supercharger. A bypass pipe extends from a main body of the screw supercharger to an upstream intake air pipe such that part of the intake air compressed to a certain extent in the supercharger returns to an inlet of the supercharger. A duty solenoid valve is connected to the bypass pipe for controlling a flow rate of the air returning to the inlet of the supercharger through the bypass pipe. The screw supercharger is originally designed to match a low speed condition and to feed an excessive amount of air at a high speed condition. The solenoid valve allows the intake air to return to the upstream intake air pipe through the bypass pipe from the supercharger when the engine is operated at a high speed condition so that an excessive amount of air is not supplied to the engine.

Abstract: In a method for processing a rotor used for a supercharger and the like, a slanted rolling machine is used having rolls designed such that the rolls are arranged about a pass line along which a material to be molded advances. Each roll is of corn shape and has a plurality of spiral-shaped grooves formed on its side surface. A shaft member made from iron or a similar material is inserted into an aluminum alloy tube. The aluminum alloy tube with the shaft member inside it is continuously fed to the slanted rolling machine along the pass line. Then, the periphery of the aluminum alloy tube is rolled/spread by the rolls for forming spiral shaped teeth from the tube material and for metallurgically attaching the tube to the shaft member.

Abstract: There is provided a fuel cell generating set including (a) a fuel cell, (b) a Lysholm compressor, (c) a gas-liquid separation apparatus condensing humidity generated in the fuel cell into water and retaining the thus-produced water therein, and (d) an injection pump for injecting the water to an intake port of the Lysholm compressor. The water exchanges heat with air under pressure in the Lysholm compressor to thereby cool air to be discharged from the Lysholm compressor by latent heat of vaporization. The water injected from the injection pump seals a leakage path in the Lysholm compressor. The above-mentioned generating set enhances volumetric efficiency and temperature efficiency of a Lysholm compressor, which ensures that the generating set can operate with less power and the generating set can be made smaller in size and lighter in weight. In addition, it is not necessary to supply water to the generating set, because the generating set is self-sufficient with respect to water.

Abstract: A method of connecting an aluminum part with a steel part using a friction welding technique. The aluminum part is heat treated such as T6 treatment to raise its hardness. After that, the aluminum part is friction welded to the steel part. The steel part may also be heat treated to lower its hardness instead of or in addition to hardening of the aluminum part. A third part which has an intermediate hardness may be placed between the aluminum part and the steel part, and the aluminum part may be coupled with the steel part via the third part.

Abstract: A seal arrangement for an engine-driven supercharger to prevent burning and abnormal wear of an rubber-made oil seal fitted on a shaft of a rotor of the supercharger. The supercharger includes a housing, a rotor chamber is formed in the housing and the rotor is rotatably placed in the rotor chamber. A shaft chamber is formed next to the rotor chamber. The rotor shaft projects from the rotor chamber into the shaft chamber in a longitudinal direction of the rotor. A bearing is provided inside the shaft chamber for supporting the rotor shaft at a free end of the rotor shaft. A lubrication oil is fed to the bearing. The supercharger sucks external air into the rotor chamber by making the rotor chamber pressure negative and rotates the rotor for compressing the air in the rotor chamber. The oil seal is fitted on the rotor shaft between the bearing and the rotor chamber for defining an oil chamber in the shaft chamber between the oil seal and the bearing.

Abstract: A pulley assembly for a driven shaft is disclosed. The pulley assembly includes a pulley to which a turning force is transferred from a driving unit; a sleeve fixedly mounted to a casing of the driven unit through which the driven shaft passes with a clearance between an outer periphery of the driven shaft and an inner periphery of the sleeve; a bearing structure for bearing the pulley rotatably about an axis of the driven shaft, the bearing structure being disposed between the pulley and the sleeve; and a torque transferring structure for transferring the turning force transferred to the pulley to the driven shaft, the torque transferring structure being interposed between the pulley and the driven shaft.

Abstract: A seal device for a Lysholm compressor has a carbon seal ring and a metal maintaining ring arranged peripherally of a shaft of a male or female rotor, the seal ring being pressed against the maintaining ring to achieve sealing. Square root of a sum of square of surface roughness of the seal ring and square of surface roughness of the maintaining ring is in the range of 0.8 to 2.5 Z, which prevents occurrence of blisters on a surface of the seal ring and leaked oil amount can be within the leakage permissible level.

Abstract: In a lysholm compressor having intermeshing male and female rotors rotated in a casing to compress an axially flowing gas, discharge-side shafts of the rotors are borne by discharge-side bearings to fix the discharge-side shafts in thrust direction while suction-side shafts of the rotors are borne by suction-side bearings to allow the suction-side shafts to move in the thrust direction. Clearances of the rotors to the casing are properly set or selected.