Abstract: An oil impregnated porous bearing unit includes an arrangement wherein an oil impregnated porous bearing containing ferro-fluid is fixed in a non-magnetizable housing, a ring shaped permanent magnet is disposed so that the ferro-fluid will exist in a gap between a rotary shaft, whereon the ring shaped permanent magnet is fixed, and the oil impregnated porous bearing, and the ferro-fluid circulates between a slide plane of the bearing and a body of the oil impregnated porous bearing with rotation of the rotary shaft by utilizing the magnetic attractive force of the permanent magnet and a capillary phenomenon in the oil impregnated porous bearing.

Abstract: A magnetic fluid bearing unit has a bearing housing, a bearing member having magnetic fluid as a lubricating agent, a rotary body rotatively supported by the bearing member, an upper permanent magnet arranged inside the bearing housing, and a lower permanent magnet arranged inside the bearing housing, the bearing member being sandwiched by the upper permanent magnet and the lower permanent magnet. The bearing member is a radial porous oil-containing bearing member in which the magnetic fluid is impregnated. The upper permanent magnet is set to have one direction of magnetic pole orientation, and the lower permanent magnet is set to have the same direction of magnetic pole orientation as the upper permanent magnet. The bearing member is sandwiched by the upper permanent magnet and the lower permanent magnet to confine the magnetic fluid. Over a wide range of rotation speeds, the leakage and the scattering of the magnetic fluid from the bearing unit can be prevented.

Abstract: Disclosed is a sintered iron alloy, a method of manufacturing the same, a powdered mixture used for manufacturing the same and a method of modifying the surface of the iron alloy. The sintered iron alloy is produced by compacting a powdered mixture comprising: boron or boron compound which is selected from the group consisting of boron oxide, boron sulfide, boron halide, boron hydride, boric acid, borate and tetrafluoroborate; 0.1 to 2.0% by weight of graphite; and iron, and sintering it. Alternatively, the iron alloy is produced by impregnating a modifier containing boron or boron compound, into a green compact, a presintered compact or sintered body which contains iron and carbon, and heating it.

Abstract: Disclosed is a manufacturing process of a sintered connecting rod assembly comprising a first member with a projection and a second member with a concavity in which the first member and the second member are mated with each other by engaging the projection with the concavity. A powdered raw material is compacted into a first compact and a second compact for the first and second members, wherein the projection of the first compact has a width slightly larger than the width of the concavity of the second compact. Then the projection of the first compact is engaged with the concavity of the second compact to mate the first compact with the second compact, thereby the projection and the concavity are tightly pressed against each other. After sintering the mated first and second compacts, they are forced to release the projection from the concavity. The die for compacting the raw material has a whole cavity and a removable core for dividing the whole cavity into two cavities.

Abstract: The present invention relates to a method for producing, without quench-hardening process, a ferrous sintered alloy having satisfactory strength which is equal to that of the conventional ferrous sintered quenched material, and the method comprises the steps of: preparing a powder mixture by adding, in weight ratios, 1 to 2% of copper powder, 1 to 3% of Ni powder, and graphite to a ferrous alloy powder consisting of 3 to 5% of Ni, 0.4 to 0.7% of Mo, and the remainder Fe, the quantity of said graphite being determined such that the C-content after sintering is 0.2 to 0.7%; compacting said powder mixture in a tool to form a green compact; sintering said green compact in a non-oxidizing atmosphere at a temperature in the range of 1130.degree. to 1230.degree. C.; and cooling the sintered product in the sintering furnace at a rate of 5.degree. C./min. to 20.degree. C./min.

Abstract: A bearing unit in which two oil sintered slide bearings are fitted in a bearing space of non-magnetic bearing housings to be spaced away from each other and a magnetic fluid is interposed between a rotary shaft and the oil sintered slide bearings to rotatably support the rotary shaft. The rotary shaft is made from a material having permeability, and a ring-shaped permanent magnet is fixedly provided between the two oil sintered slide bearings to be spaced therefrom. The magnetic fluid is held between the two oil sintered slide bearings to be circulated.

Abstract: The Al-Si sintered alloy having good mechanical strength and elongation and is especially excellent in wear resistance, and a method for producing the same. The sintered alloy consists of 2.4-23.5% Si, 2-5% Cu, 0.2-1.5% Mg, 0.01-1% of transition metals and the balance of aluminum and unavoidable impurities, and has a dapple grain structure of an Al-solid solution phase and an Al-Si alloy phase containing dispersed pro-eutectic Si crystals having a maximum diameter of 5-60 .mu.m either in the whole body or in the surface contact portion, and the area ratio of the Al-solid solution phase in the grain structure is in the range of 20-80%.

Abstract: A method of manufacturing sintered Al-Si series alloy parts having complex configurations such as scroll shaped parts wherein Al-Si series alloy powder solidified via rapid cooling prepared by adding effective components such as Si, Cu, Mg, Fe, Mn, Zr and Ce to Al is compression molded, the molded body is sintered by heating via an electrical current conduction in a form of a plasma discharge and then the sintered body is worked by pressing, thereby the parts having complex configurations of light weight, high mechanical strength and toughness is manufactured with a simple installation and reduced processing manhours, and with a high efficiency and at a low cost.