Hitachi Powdered Metals Co., Ltd.

Hitachi, Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Hitachi Koki Co., Ltd.

Minebea Company, Limited

Hideo Shikata

Jun Sakai

Katsutoshi Nii

Hidekazu Tokushima

Zenzo Ishijima

Hideo Urata

Junichi Ichikawa

Kei Ishii

Motohiro Miyasaka

Tadayuki Tsutsui

Michihiro Aizawa

Jun-ichi Ichikawa

Shuji Sasaki

Bo Hu

Keiichi Nakamura

Hayato Matsuda

Tadashi Iizuka

Sumihisa Kotani

Yusaku Nakagawa

Shoichi Nakashima

Toshikazu Takehana

Jun Hirose

Yasuo Kamitsuma

Shoji Kawase

Osamu Mawatari

Katsuhiko Ueda

Tamio Takada

Tadayoshi Yano

Yoshihiro Kobayashi

Jun-ichi Ueda

Syuji Sasaki

A fluid dynamic pressure effect can be sufficient without receiving a large effect of viscous friction of lubricating oil with changes in the environmental temperature in which it is used, and smooth starting of the rotating shaft can be ensured by regulating the gap between the rotating shaft and bearing within a suitable range. An outer diameter of the bearing, D, a length in an axial direction of the bearing, L, a gap at a radial side which is between the rotating shaft and the bearing, C, and an inclining height of the bearing end surface to which the flange is faced, &#x3b4;, satisfy the expression L/D&#x3c;C/&#x3b4;. It is preferable that the inclining height, &#x3b4;, be 2 to 6 &#x3bc;m, the inner diameter of the bearing be 1 to 3 &#x3bc;m, and the gap at a radial side, C, be 1 to 4 &#x3bc;m.

Dynamic bearing unit

A process for producing a sintered aluminum alloy in which dispersion of tensile strength is small and elongation property and fatigue strength are improved. In this process comprising the steps of compacting powder mixture containing rapidly solidified Al&#x2014;Si powder, Al powder and Cu powder or Cu alloy powder into a green compact; sintering the green compact with optional heat treatment, Al powder having a maximum particle size smaller than a specific range, an average particle size within a specific range and specific particle size distribution, is used.

Process for producing sintered aluminum alloy

A bearing unit comprises a bearingformed of a sintered metal in which a magnetized magnetic powder is dispersed in its matrix and at least pores exposed on a bearing surface thereof are sealed by impregnation with a resin; a non-magnetic housingaccommodating the bearing; and a lubricating fluid M made of a magnetic fluid.

Bearing unit, production method therefor and spindle motor

Disclosed is a process for manufacturing a sintered slide bearing. A sintered porous bearing body is prepared from a powdered metal material and a resin material in a fluidable state is penetrated into the sintered porous bearing body. The resin material in the sintered porous bearing body is hardened, and the sintered porous bearing body after the hardening of the resin material is repressed to reduce a gap produced between the sintered porous bearing body and the hardened resin material by volume reduction caused on the resin material at the hardening.

Process for manufacturing sintered slide bearing

Disclosed is a thin plate member for forming a semiconductor package, having a recess for receiving a semiconductor chip. The thin plate is composed of sintered metal, e.g. sintered copper or sintered alluminum alloy. A sintered metal body being porous and having a shape which is close to the shape of the thin plate member is prepared, and it is sized into the shape of the thin plate member. The sintered alluminum alloy comprises 0.4 to 0.8% by weight of magnesium, 0.2 to 0.6% by weight of silicon and the balance aluminum and has a structure comprising an aluminum phase being formed of aluminum particles and an alloy phase being composed of magnesium, silicon and aluminum and interposing between the aluminum particles, and the sintered copper has a metallographic structure comprising a phase of copper particles.

Thin plate member for semiconductor package and manufacturing method therefor

Sheet metal member, method of manufacturing same, and heat radiation

There is disclosed a method for manufacturing an Fe-based sintered alloy which is superb in machinability. This process comprises the steps of coating a paste-like coating agent including a compound of boron to a surface of a compact of Fe-based or Fe, Cu-based sintered alloy powder including carbon or a pre-sintered compact obtained by heating the compact at a diffusion temperature or less of carbon, and sintering a resultant compact or a pre-sintered compact at a diffusion temperature or more of carbon. An Fe-based sintered alloy manufactured through this process and a bearing cap made of such an Fe-based sintered alloy are also disclosed. In the invention, a film including a compound of boron and pyrolytic resin can be used instead of the paste-like coating agent.

Fe-based sintered alloy manufacturing process, Fe-based sintered alloy

There is provided a connecting rod including a connecting rod body and a cap having excellent alignment properties, and a method of producing such a connecting rod. A connecting rod body and a cap are produced through the steps of molding green compacts respectively corresponding to the connecting rod body and the cap; sintering and unifying both the green compacts; forging the resultant sintered product in a mold; and fracturing the resultant forged product. The green compact corresponding to the cap and/or the green compact corresponding to the connecting rod body includes opposite circumferential end faces formed with one or more projection. A clearance c is formed between both circumferential end faces of the sintered product due to the projection. With this clearance c, both the circumferential end faces are formed with recesses and projections which are fitted to each other during the forging process and which are relatively large and thus have large biting amounts. During the fracturing process, the recesses and the projections are separated into two pieces.

Process for producing connecting rod

A plurality of blanks divided at a division end face 5 or a blank-bonded product comprising a plurality of blanks sintered and bonded together are or is compressed in the same mold, so that they are plastically deformed until the division end faces 5 are cohered. Thereafter, a load is applied to the plastically worked product in a direction of breaking of the division end faces 5 to break the division end faces 5 and divide the plastically worked product into a plurality of members. In this manner, a split type mechanical part having irregularities meshed with each other on mating faces and easily positionable relative to each other can be produced with a good dimentional accuracy.

Process for producing split type mechanical part

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. In addition, a spiral groove may be provided in an exterior circumferential surface of the permanent magnet fixed to the rotary shaft or in an interior circumferential surface of the housing facing the above exterior circumferential surface of the permanent magnet in order to generate dynamic pressure at the spiral groove portion with rotation of the rotary shaft so as to supply ferro-fluid to the oil impregnated porous bearing.

Oil impregnated porous bearing units and motors provided with same

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. The bearing unit for a compact size motor having a high rotation accuracy can be obtained.

Magnetic fluid bearing unit structure and motor having the same

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.

Manufacturing process of sintered iron alloy improved in machinability,

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.

Manufacturing process of connecting rod assembly and compacting die

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.

Method for producing ferrous sintered alloy having quenched structure

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.

Growing community of inventors

Matsudo, Japan

Hideo Shikata