Abstract: A securing surface of a housing comprises a deformation region, which deforms radially outward by a predetermined quantity during press fitting of a thrust member, and another region. The deformation region has a tapered shape that gradually reduces in diameter in the downward direction, and is receded radially inward relative to the other region of the securing surface, by an amount equivalent to the amount of outward deformation thereof during press fitting. When the thrust member is press fitted into the inner periphery of a press fitting portion of the housing, the securing surface of the housing becomes substantially straight along entire axial region L thereof.

Abstract: A dynamic bearing device includes: a housing; a bearing sleeve arranged inside the housing; a shaft member rotating relative to the housing and the bearing sleeve; and a radial bearing portion supporting the shaft member radially in a non-contact manner by a dynamic pressure action of a lubricant generated in a radial bearing clearance. The housing is formed of a leadless brass whose Sn content is regulated to 0.01 wt % or less.

Abstract: A dynamic bearing device is provided, which can prevent abrasion powder generated when a sealing member is pushed into an inner circumference of a housing from entering the housing. A sealing member is inserted into an inner circumference of an opening of a housing with an adhesive interposed therebetween The adhesive moving forward in a pushing direction of the sealing member is retained by a capillary action in a lower tapered space between an outer circumference of the sealing member and the inner circumference of the housing. Abrasion powder is captured by the adhesive in the tapered space so as to be confined in the adhesive as a result of the setting of the adhesive.

Abstract: The thrust member is inserted into the inner circumferential surface of the housing, to make the end face of the thrust member contact with the lower side end face of the flange portion, and at the same time, to make the upper side end face of the flange portion contact with the lower side end face of the bearing sleeve. This stated is that the thrust bearing gap is zero. Then, the thrust member is made to relatively move with respect to the housing and the bearing sleeve in the axial direction together with the axis member, with a dimension ?(?=?1+?2) that is equivalent to the sum of the thrust bearing gap (size is ?1) of the first thrust bearing portion and the thrust bearing gap (size is ?2) of the second thrust bearing portion. Then, as the thrust member is fixed to the housing at that position, the predetermined thrust bearing gap ?(?=?1+?2) is formed.

Abstract: There is provided a durable low-torque lubricating oil for bearings and fluid dynamic bearings, porous oil-impregnated bearings and hydrodynamic type porous oil-impregnated bearings suitable for use as bearings in small-sized spindle motors for information equipment. The lubricating oil composition comprising (A) a diester of a monovalent aliphatic alcohol containing 6-10 carbon atoms and a saturated aliphatic dicarboxylic acid containing 10 carbon atoms as base oil and (B) 3-20% by weight of a low-viscosity lubricating oil with a kinematic viscosity of less than 11 mm2/s at 40° C., a fluid dynamic pressure bearing unit or a porous oil-impregnated bearing unit containing said lubricating oil composition or a spindle motor provided with said bearing unit.

Abstract: The thrust member is inserted into the inner circumferential surface of the housing, to make the end face of the thrust member contact with the lower side end face of the flange portion, and at the same time, to make the upper side end face of the flange portion contact with the lower side end face of the bearing sleeve. This stated is that the thrust bearing gap is zero. Then, the thrust member is made to relatively move with respect to the housing and the bearing sleeve in the axial direction together with the axis member, with a dimension ?(?=?1+?2) that is equivalent to the sum of the thrust bearing gap (size is ?1) of the first thrust bearing portion and the thrust bearing gap (size is ?2) of the second thrust bearing portion. Then, as the thrust member is fixed to the housing at that position, the predetermined thrust bearing gap ?(?=?1+?2) is formed.

Abstract: A hydrodynamic bearing unit is provided, by which the touch between oil and a sealing member in a housing is prevented to prevent oil leakage. A bearing member made of a sintered lubricant-containing metal is disposed along the inner periphery of the housing and a spindle is supported in a non-contact manner by the hydrodynamic oil pressure that is generated in a bearing gap by the rotation of the spindle. The opening of the housing is sealed by the sealing member. A ventilation path is formed so as to communicate a sealed space enclosed by the distal end of the spindle at the bottom of the housing, the bearing member and the housing with open air. An oil reservoir is formed between the inner periphery of the housing and the outer periphery of the bearing member at the end portion of the opening side of the housing. The oil reservoir is made so as to communicate with the ventilation path.

Abstract: A securing surface of a housing comprises a deformation region, which deforms radially outward by a predetermined quantity during press fitting of a thrust member, and another region. The deformation region has a tapered shape that gradually reduces in diameter in the downward direction, and is receded radially inward relative to the other region of the securing surface, by an amount equivalent to the amount of outward deformation thereof during press fitting. When the thrust member is press fitted into the inner periphery of a press fitting portion of the housing, the securing surface of the housing becomes substantially straight along entire axial region L thereof.

Abstract: A hydrodynamic bearing device with reduced costs is provided. A housing with a bearing sleeve housed therein is formed by drawing. A cup shaped thrust member is positioned in a bottom part of the housing, and by bringing this thrust member into contact with a lower end surface of the bearing sleeve, the widths of thrust bearing gaps within first and second thrust bearing parts are set to prescribed values.

Abstract: The thrust member is inserted into the inner circumferential surface of the housing, to make the end face of the thrust member contact with the lower side end face of the flange portion, and at the same time, to make the upper side end face of the flange portion contact with the lower side end face of the bearing sleeve. This stated is that the thrust bearing gap is zero. Then, the thrust member is made to relatively move with respect to the housing and the bearing sleeve in the axial direction together with the axis member, with a dimension &dgr;(&dgr;=&dgr;1+&dgr;2) that is equivalent to the sum of the thrust bearing gap (size is &dgr;1) of the first thrust bearing portion and the thrust bearing gap (size is &dgr;2) of the second thrust bearing portion. Then, as the thrust member is fixed to the housing at that position, the predetermined thrust bearing gap &dgr;(&dgr;=&dgr;1+&dgr;2) is formed.

Abstract: There is provided a durable low-torque lubricating oil for bearings and fluid dynamic bearings, porous oil-impregnated bearings and hydrodynamic type porous oil-impregnated bearings suitable for use as bearings in small-sized spindle motors for information equipment. The lubricating oil composition comprising (A) a diester of a monovalent aliphatic alcohol containing 6-10 carbon atoms and a saturated aliphatic dicarboxylic acid containing 10 carbon atoms as base oil and (B) 3-20% by weight of a low-viscosity lubricating oil with a kinematic viscosity of less than 11 mm2/s at 40 ° C., a fluid dynamic pressure bearing unit or a porous oil-impregnated bearing unit containing said lubricating oil composition or a spindle motor provided with said bearing unit.

Abstract: An inner space of a housing sealed with a seal member as well as internal pores of a bearing member (pores in a porous structure) are filled with a lubricating oil without the presence of air, so that the oil surface of the lubricating oil is within a seal space. Under a reduced pressure of 100 Torr, no lubricating oil leaks outside of the housing even at any attitude of the fluid lubricated bearing device such as normal, inverted, or horizontal attitude.

Abstract: A rolling bearing in which the attainment of excellent current-carrying capability is compatible with cost reduction. The rolling bearing comprises an inner ring, an outer ring, and a plurality of rolling elements arranged between the inner and outer rings, oil films being interposed between the rolling elements and raceway surfaces of the-rings. Here, the inner raceway surface and the outer raceway surface are made coarser to such a surface roughness (Ra=0.1 &mgr;m or so) that they come into metal contact wit the rolling elements for electric connection.

Abstract: A hydrodynamic oil-impregnated sintered bearing unit 1 are comprised a hydrodynamic oil-impregnated sintered bearing 1a, a housing 1b, and a thrust bearing portion for thrust-supporting a shaft. A sealing washer 20 made of metal or resin material is arranged on an opening-portion side of the housing 1b, and that, of a surface of the shaft 2, at least on a region including a portion opposite to the sealing washer 20 a thin layer 21 of a fluorine-containing polymer is formed.

Abstract: A hydrodynamic oil-impregnated sintered bearing unit 1 are comprised a hydrodynamic oil-impregnated sintered bearing 1a, a housing 1b, and a thrust bearing portion for thrust-supporting a shaft. A sealing washer 20 made of metal or resin material is arranged on an opening-portion side of the housing 1b, and that, of a surface of the shaft 2, at least on a region including a portion opposite to the sealing washer 20 a thin layer 21 of a fluorine-containing polymer is formed.

Abstract: A hydrodynamic bearing unit is provided, by which the touch between oil and a sealing member in a housing is prevented to prevent oil leakage. A bearing member made of a sintered lubricant-containing metal is disposed along the inner periphery of the housing and a spindle is supported in a non-contact manner by the hydrodynamic oil pressure that is generated in a bearing gap by the rotation of the spindle. The opening of the housing is sealed by the sealing member. A ventilation path is formed so as to communicate a sealed space enclosed by the distal end of the spindle at the bottom of the housing, the bearing member and the housing with open air. An oil reservoir is formed between the inner periphery of the housing and the outer periphery of the bearing member at the end portion of the opening side of the housing. The oil reservoir is made so as to communicate with the ventilation path.