Abstract: In a Roots displacement fluid machine (5) comprising rotors (15, 17) meshed with each other in a tooth trace (57, 59) formed in parallel to a rotating central axis, and a casing (13) having a rotor chamber (33) rotatably receiving the rotors (15, 17), a fluid inlet port for a fluid and a fluid outlet port, an inclined surface (67) forming an angle .theta. with respect to an opposing surface (65) of the rotor chamber (33) is disposed at least in a tip end of the end portion of the rotor (15), and a gap (69) is formed with respect to the opposing surface (65).

Abstract: A cast screw rotor has an opened lightening or reduced weight hole formed inside each thread portion. The opened hole is formed along torsion of the thread portion, and a shaft is inserted into an axial hole. The screw rotor is manufactured by a method in which each of the thread portions and the axial hole are formed on the basis of the reduced weight hole.

Abstract: An object of the present invention is to provide a rotor of a fluid machine in which the rotor can be made light in weight and moment of inertia of the rotor can be reduced and the rotor can be easily balanced in its rotating direction. In this rotor of a fluid machine, a fluid is compressed and pumped by a pair of rotors engaged with each other. A hollow portion is formed within a tooth stripe portion of one rotor. A thickness forming portion for a balance correction is formed in an opening portion of this hollow portion to balance the rotor in its rotating direction and is projected on an inner circumferential side of the hollow portion.

Abstract: There are provided male and female rotors, which engage with each other at screw-shaped tooth trace portions formed on the rotor bodies; a compressor casing which houses these rotors and has a suction port on one side in the axial direction and a discharge port on the other side in the axial direction; hollow portions which are provided in the tooth trace portions of the male screw rotor and communicate with the suction port; and partition walls which are provided at the end on the discharge port side of the tooth trace portions and block the hollow portions.

Abstract: A shaft hole 69 in a cast rotor main body 67 has a hollow space 75 and an opening 79 in a tooth trace 73 formed by using a core. A hollow screw rotor 35 is formed by fixing a rotor shaft 47 in this shaft hole 69. A straight portion 81 to be chucked at the time of machining is formed at the inner peripheral side of the opening 79.

Abstract: In a supercharging device for an internal combustion engine including an air compressor, a bearing holder, and a planetary gear type of speed increasing gear device with an internal gear, a pair of pinion gears, and a sun gear, a oil channel guiding lubricating oil to the plain bearings to form oil film damper is provided in the bearing holder. In the bearing holder located between the pinion gears, an oil guide means for directing the lubricating oil, splashed from the pinion gears toward the oil guides, in the direction of the sun gear, is provided. A thrust washer can be arranged between the plain bearings to receive the thrust force of the impeller shaft.

Abstract: A belt type nonstep variable speed pulley and gear mechanism conveys an engine rotational driving force towards an auxiliary machinery in a vehicle while changing engine speeds. It includes an axle, a fixed flange unitarily rotatable and fixedly mounted in an axial direction which extends along the axle, a movable flange unitarily rotatable with the axle and movable in the axial direction. The movable flange has one side face arranged against the fixed flange. The variable speed pulley device also has a belt provided between the fixed flange and the movable flange, a cam member having a predetermined cam face which is pressed by thrust force in the axle direction for moving the movable flange, a fixed member arranged against an other side face of the movable flange and unitarily rotatable with the axle, and a flyweight arranged between the fixed member and the movable flange so as to contact with and press the cam face by centrifugal force.

Abstract: An induction furnace is disclosed, including a porous furnace wall formed by sintering castable refractory material. Gas passageways are formed in the furnace wall, and a common pipe connecting the gas passageways is connected to a gas conveying unit provided outside of the furnace wall. An outer gas-blocking layer surrounds the furnace wall.

Abstract: A shaft hole 69 in a cast rotor main body 67 has a hollow space 75 and an opening 79 in a tooth trace 73 formed by using a core. A hollow screw rotor 35 is formed by fixing a rotor shaft 47 in this shaft hole 69. A straight portion 81 to be chucked at the time of machining is formed at the inner peripheral side of the opening 79.