Abstract: A bearing unit comprises a bearing 60 formed 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 housing 90 accommodating the bearing 60; and a lubricating fluid M made of a magnetic fluid.

Abstract: A production method for a sintered bearing, comprises compacting a raw metallic material powder into a bearing green compact; sintering the green compact into a sintered compact; and forming a resin coating over the entire surface of the sintered compact by electrodeposition.

Abstract: A mechanical fuse has further improved and stabilized fatigue limit ratio, and can obtain high reliability under a using condition in which cyclic loading is applied. The mechanical fuse comprises Fe-based sintered alloy comprising at least one element of P at 0.15 to 1.5 mass %, Si at 0.4 to 2.0 mass %, and Mn at 1.0 to 4.0 mass %, and the remainder consisting of Fe and inevitable impurities, wherein an iron oxide layer is formed on a pore inner wall, and the pores have roundness of 0.004 or more. A method of production therefore is also provided.

Abstract: The present invention provides a production method for a sintered metal-ceramic layered compact, comprising steps of: filling and layering a metal powder and a ceramic powder, or filling and layering a metal powder, a mixed powder of a metal powder and a ceramic powder, and a ceramic powder; forming a green compact of the layered powders by compacting the layered powders; and sintering a layer including the metal of the green compact at a temperature of lower than a melting point of the metal by heating by irradiation of microwaves in a non-oxidizing atmosphere.

Abstract: A spindle motor having a bearing housing and a thrust bearing fitted in the bearing housing at the lower end of the latter, in which an inclined part is formed on the outer peripheral edge at the lower end of the thrust bearing, and the outer diameter part of the thrust bearing is fitted in a coupling bore formed in the end surface of the bearing housing, the end surface of the bearing housing being pressed uniformly in the axial direction over the entire circumference around the coupling bore to cause the bearing housing to plastically flow around the coupling bore in order to cover the above-mentioned inclined part of the thrust bearing. The above-mentioned covering part formed in the bearing housing through plastic flow can exhibit a high bonding strength between the bearing housing and the thrust bearing in the spindle motor without deteriorating the sealing ability of the spindle motor, due to a shearing force and a residual contact pressure of the covering part.

Abstract: Disclosed is a die for compacting a powdered material. The die has a die body having a penetrating die cavity to which a couple of punches are adapted to apply for pressing the powdered material to be supplied to form a compact, and a die holder having a bore into which the die body is shrink fitted. The die cavity is provided with a coating composed of a material which is selected from the group consisting of titanium carbide, titanium nitride, alumina, titanium cyanide, hafnium nitride, chromium nitride, tungsten carbide and DLC, and the die holder is composed of a steel material which is prepared by tempering at a temperature higher than a treatment temperature at which the coating is provided on the die cavity. The die cavity is tapered at a ratio within a range of 1/5,000 to 1/1,000.

Abstract: A method of producing graphite powder for a negative electrode of a lithium ion secondary cell excellent in discharge/charge efficiency (Coulomb efficiency) and having a high capacity retention rate, wherein 0.01 to 10 wt % (on the basis of the graphite material) of a starch derivative having C6H10O5 as a basic structure or other surface active materials are allowed to be adsorbed by or to coat the surface of a graphite material for a negative electrode capable of occluding and releasing lithium ions and furthermore at least one kind of metal elements selected from the group consisting of lithium, calcium, magnesium, sodium and potassium is added.

Abstract: A spindle motor comprises a housing 10 including a through hole with a pair of apertures, one of the apertures being closed by a thrust plate 70 and the other aperture being open; a bearing 60 accommodated in the housing 90; a rotating shaft 30 inserted into the bearing 60; a displacement restraining structure for restraining movement of the rotating shaft 30 toward the open aperture by engaging the rotation shaft 30 with the bearing 60; a rotating member secured to the rotating shaft; and a motor generating electromagnetic function for rotating the rotating member. The through hole of the housing 90 includes a large diameter portion 92A at the thrust plate 70 side and a small diameter portion 92B at the open aperture side, and a stepped portion 93 is formed at a transition portion between the large diameter portion 92A and the small diameter portion 92B.

Abstract: 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.

Abstract: A silent chain power transmitting apparatus has an endless link chain having a plurality of link plates (11A,11B,11C, . . . ) connected together, and sprocket wheels (20). Each of an inside flank (13) and an outside flank (14) of each link plate (11A,11B,11C, . . . ) is profiled by a circular shape of a same radius (&rgr;) of curvature whose individual center (d1, . . . ) of curvature is on a chain pitch line (PL). Each tooth (22) of the sprocket wheel (20) is profiled by a circular shape of the same radius(&rgr;) of curvature, which is meshed with corresponding inside flank (13) and outside flank (14) of each link plate (11A,11B,11C, . . . ). A power of the sprocket wheel (20) is transmitted to the link plates (11A,11B,11C, . . . ) in linear contact (or surface contact) momentarily, not in point contact.

Abstract: A corrosive resistant metal material covered with a conductive substance suitable for use in a component material requiring conductivity and corrosion resistance like electrical conductive material, electrical contact, electromagnetic wave shield, electrochemical electrode or antistatic material, specifically for component material requiring conductivity in sever condition of corrosive environment is provided. A corrosive resistant metal material covered with a conductive substance is formed by cladding a corrosive resistant metal selected from the group consisting of titanium, zirconium, tantalum, niobium and alloy thereof on a conductive metal selected from the group consisting of iron, aluminum, copper, titanium, magnesium, zirconium, tantalum, niobium, tungsten, nickel, chrome and alloy thereof, and covering a conductive surface finishing layer over surface of a corrosive resistant metal layer with a mixture of conductive substance and resinous binder.

Abstract: A valve seat is provided in which wear resistance can be ensured by optimizing the matrix structure without dispersing of expensive hard particles, and therefore the machinability can be improved and the holding down of cost can be achieved. The valve seat exhibits a metallographic structure consisting of only bainite single phase or only a mixed phase of bainite and martensite, has an area ratio of bainite and martensite in cross section of 100:0 to 50:50, and has a matrix hardness of 250 to 850 Hv.

Abstract: Material powder 17 is filled in a cavity 16 which is composed of a die 12 having a die hole 11 in a shape matching the contour of a green compact and a lower punch 13. The material powder 17 is temporarily compressed by an upper punch 14 and the lower punch 13 to obtain a preform 18. A punch-out pin 15a is inserted into the preform 18 to punch out a shape of a through-hole 3. The preform 18 is pressurized and compressed by both of the upper and lower punches 14, 13 to obtain a green compact 19. The punch-out pin 15a is pulled out from the green compact 19 and the green compact 19 is taken out from the cavity 16. Further, the green compact 19 is sintered and a pair of leg parts 24 connected continuously at a base part 23 and an undercut part 25 between the leg parts 24 are formed by cutting off a part of a peripheral wall 26 of a through-hole 25a.

Abstract: Disclosed is a sintered alloy material for valve guides, containing: 1.5% to 4% by mass of carbon; 1% to 20% by mass of copper; 0.1% to 2% by mass of tin; 0.01% or more than 0.01% and less than 0.1% by mass of phosphorus; and an iron base. The metallographic structure of the sintered alloy material has a matrix phase composed mainly of pearlite, and a free carbon phase being dispersed in the matrix phase.

Abstract: The field emission type cathode. (K) is made as the multilayered structure (33) in which the conductive platelike corpuscles 30 are piled, whereby an edge portion of end surface of a field emission type cathode K for emitting electrons is formed sharply and easily.

Abstract: A conventional plain bearing, in which dynamic pressure is generated by means of lubricating oil, has been assembled in such a way that the whole bearing device is assembled and then the lubricating oil is poured in the interior. As a result, residual air bubbles are produced to cause lowering of the dynamic pressure. The present invention uses magnetic fluid as lubricating oil, and adopts, for enclosing the fluid, a method in which at the time of assembling a spindle motor, a permanent magnet is used, magnetic fluid of a specified amount is previously held in a bearing unit by the magnetic attraction force, and after the insertion of a shaft, the magnetic fluid is supplied into a narrow space of a bearing part by a capillary attraction.

Abstract: A wear resistant sintered member exhibits superior wear resistance at the same level as those of the conventional materials without using a Co-based hard phase is provided. A first hard phase comprising Mo silicide particles dispersed in an Fe-based alloy matrix of the first hard phase and a second hard phase comprising a ferrite phase or a mixed phase of ferrite and austenite having a higher Cr concentration than the Fe-based alloy matrix surrounding a core consisting of Cr carbide particles, are diffused in an Fe-based alloy matrix, the Mo silicide particles are contained in the first hard phase in an amount of 3 to 25 % by area, and the Cr carbide particles are contained in the second hard phase in an amount of 3 to 30 % by area.

Abstract: A sintered metal sprocket for a silent chain is produced by the following steps. A base mixture is prepared, which contains a powder metallurgical iron powder, a lubricant and a graphite powder. Then, the base mixture is subjected to a compression molding while being heated at above approximately 100° C. thereby to produce a green compact. Then, the green compact is subjected to a sintering at a temperature above approximately 1180° C. For much improving the mechanical performance of the sprocket thus sintered, the same may be subjected to a carbonizing hardening or an induction hardening.

Abstract: A turbo component for a turbocharger in which heat resistance, corrosion resistance, and wear resistance is superior, and in which the cost is further lowered, is provided. In the turbo component, the overall composition is, in ratio by mass, Cr: 23.8 to 44.3%, Mo: 1.0 to 3.0%, Si: 1.0 to 3.0%, P: 0.1 to 1.0%, C: 1.0 to 3.0%, and the balance of Fe and inevitable impurities, and carbide is dispersed in the matrix at a density ratio of 95% or more.

Abstract: An inexpensive mechanical fuse having a high fatigue limit ratio and high rupture reliability, and superior in forming performance, and a method of manufacturing the same are presented. The mechanical fuse is composed of Fe-based sintered alloy, and comprises an inner rim 2 fixed to one power transmission shaft, an outer rim 3 fixed to the other power transmission shaft, and plural arms 4 for linking the inner rim 2 and outer rim 3, which are formed integrally. The arms 4 include rupture portions 6 which are ruptured when exposed to an overload torque. By treating in steam, an iron oxide phase is formed in the surface layer and pore inner wall. The iron oxide phase is effective to form round pores and lower the notch sensitivity. As a result, the fatigue strength and fatigue limit ratio are enhanced.