Hitachi Powdered Metals Co., Ltd.

Hitachi, Ltd.

Hitachi Chemical Company, Ltd.

Other

Minebea Company, Limited

Hidekazu Tokushima

Katsutoshi Nii

Hideo Shikata

Hideaki Kawata

Motohiro Miyasaka

Toshikazu Takehana

Tadayoshi Yano

Michihiro Aizawa

Daisuke Fukae

Jun Hirose

Naoki Nishizawa

Yuji Yoshitomi

Shigeyuki Sakurai

Hideki Akita

Osamu Gokita

Makoto Sugaya

Osamu Mawatari

Tsutomu Nozaki

Takeshi Yanase

Akiko Satou

An iron-based sintered alloy for sliding member, in which seizure resistance is improved, and a production method therefor, are provided. The iron-based sintered alloy for sliding member consists of, by mass %, 10 to 30% of Cu, 0.2 to 2.0 % of C, 0.03 to 0.9 % of Mn, 0.36 to 3.65% of S, and the balance of Fe and inevitable impurities in the overall composition. The iron-based sintered alloy for sliding member exhibits a metallic structure in which copper phases and pores are dispersed in the matrix that includes mainly a martensite structure and sulfide particles are dispersed in the matrix and the copper phases. The sulfide particles are dispersed at 1 to 30 vol. % with respect to the matrix.

Iron-based sintered alloy for sliding member and production method therefor

An iron-based sintered sliding member consists of, by mass %, 0.1 to 10% of Cu, 0.2 to 2.0% of C, 0.03 to 0.9% of Mn, 0.52 to 6.54% of S, and the balance of Fe and inevitable impurities. The iron-based sintered sliding member satisfies the following First Formula in which [S %] represents mass % of S and [Mn %] represents mass % of Mn in the overall composition. The iron-based sintered sliding member exhibits a metallic structure in which pores and sulfide particles are dispersed in the matrix that includes a martensite structure at not less than 50% by area ratio in cross section. The sulfide particles are dispersed at 3 to 30 vol. % with respect to the matrix.[S %]=0.6&#xd7;[Mn %]+0.5 to 6.0&#x2003;&#x2003;First Formula

Iron-based sintered sliding member and production method therefor

The oil-impregnated sintered bearing made of iron-copper sintered alloy consisting of 10-59% of Cu, 0.5-3% of Sn, and balance of Fe and impurities, includes pores in the iron-copper sintered alloy matrix of not less than 800 per mm, has pores exposed at 20-50% by area ratio at the inner circumferential surface with diameters greater than 100 &#x3bc;m, not more than 0.5%, respectable to the total pores number. The pores number with diameters greater than 80 &#x3bc;m and not greater than 100 &#x3bc;m, not more than 0.1%, respectable to the total pores number with diameters greater than 60 &#x3bc;m and not greater than 80 &#x3bc;m is 0.5-1.5%, respectable to the total pores number, with diameters greater than 40 &#x3bc;m and not greater than 60 &#x3bc;m is 0.8-3% respectable to the total pores number, and the remainder pores are with diameters less than 40 &#x3bc;m.

Oil-impregnated sintered bearing and production method therefor

An oil-impregnated sintered bearing which does not tend to produce squealing noises is provided. The oil-impregnated sintered bearing can be used as a bearing of an electric motor that may be intermittently used for a short time, such as a bearing of a window regulator motor. The oil-impregnated sintered bearing includes pores that include middle-sized pores with circle-equivalent diameters of 45 to 63 &#x3bc;m at 0.9 to 2.5%, interparticle pores with circle-equivalent diameters of 63 to 75 &#x3bc;m at 0.1 to 1.2%, and large interparticle pores with circle-equivalent diameters of larger than 75 &#x3bc;m at not more than 3%, with respect to the total number of the pores.

A sliding bearing assembly for joints of construction equipment can be provided, in which production cost is reduced by decreasing the used amount of Cu and sulfides having high fixability to a matrix are dispersed. The sliding bearing assembly for joints of construction equipment, includes at least a shaft and a bush made of an iron-based sintered material which functions as a sliding bearing, in which the bush has the overall composition of, by mass %, 0.1 to 10% of Cu, 0.2 to 1.2% of C, 0.03 to 0.9% of Mn, 0.36 to 1.68% of S, and the balance of Fe and inevitable impurities, a metal structure has pores dispersed in a matrix mainly including a martensite structure and sulfide particles precipitated and dispersed, and the sulfide particles are dispersed at 1 to 7 volume % in the matrix.

Sliding bearing assembly

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

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.

Spindle motor and manufacture thereof

A spindle motor comprises a housing including a through hole with a pair of apertures, one of the apertures being closed by a thrust plate and the other aperture being open; a bearing accommodated in the housing a rotating shaft inserted into the bearing a displacement restraining structure for restraining movement of the rotating shaft toward the open aperture by engaging the rotation shaft with the bearing 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 includes a large diameter portion A at the thrust plate side and a small diameter portion B at the open aperture side, and a stepped portion is formed at a transition portion between the large diameter portion A and the small diameter portion B. At least a portion of the bearing is located at the large diameter portion A side of the housing and engages with the stepped portion of the housing

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

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

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

Kashiwa, Japan

Hidekazu Tokushima