Abstract: A bearing part includes a quench-hardened layer in a surface of the bearing part. The quench-hardened layer includes a plurality of martensite crystal grains. A ratio of a total area of the plurality of martensite crystal grains in the quench-hardened layer is more than or equal to 70%. The plurality of martensite crystal grains are classified into a first group and a second group. A minimum value of crystal grain sizes of the martensite crystal grains belonging to the first group is larger than a maximum value of crystal grain sizes of the martensite crystal grains belonging to the second group. A value obtained by dividing a total area of the martensite crystal grains belonging to the first group by the total area of the plurality of martensite crystal grains is more than or equal to 0.5.

Abstract: A rolling bearing includes rolling elements between an outer race and an inner race, a resin seal ring covering an opening of at least one end of a bearing space, and a filter covering an oil hole defined in the resin seal ring for capturing foreign matter contained in lubricating oil. The filter and the resin seal ring are integrated by insert molding and are made of the same material. An annular lip portion, which is separate from the resin seal ring, is in contact with the outer race. An engaged portion on a radially inner side of the resin seal ring is engaged in a recess defined in the inner race such that, during thermal expansion of the resin seal ring, the engaged portion is engaged such that the resin seal ring is movable in a radial direction relative to the inner race.

Abstract: A tapered roller bearing is used in a planetary gear speed reducer, and includes an outer race, and a retainer formed with a first annular portion, a second annular portion, and pillars. At least one retainer guiding surface (raceway) which guides the retainer in a radial direction is formed only on an inner periphery of the outer race. Guided surfaces are formed at least either on the pillars or on the first and second annular portions, and guided by the at least one retainer guiding surface. Therefore, it is possible to guide an axial central portion or both side portions of the retainer, to make the retainer less likely to tilt due to a centrifugal force, and to apply a preload to both side surfaces of the outer race.

Abstract: The present invention provides a tapered roller bearing used in a planetary gear speed reducer, and including an outer race, and a retainer formed with a first annular portion, a second annular portion, and pillars. At least one retainer guiding surface (raceway) which guides the retainer in the radial direction is formed only on the inner periphery of the outer race. Guided surfaces are formed at least either on the pillars or on the first and second annular portions, and guided by the at least one retainer guiding surface. Therefore, it is possible to guide the axial central portion or both side portions of the retainer, to make the retainer less likely to tilt due to a centrifugal force, and to apply a preload to both side surfaces of the outer race.

Abstract: A rolling bearing includes an outer bearing race and an inner bearing race defining a bearing space therebetween. Rolling elements are mounted in the bearing space. A seal device is at one axial opening of the bearing space and includes a metal ring member with through holes configured such that lubricating oil can pass through the through holes and solid foreign substances cannot pass through the through holes. One of the outer bearing race and the inner bearing race is stationary, and the other is rotatable. The metal ring member is in engagement with the stationary bearing race. A metal or resin sub-ring member, which is a separate member from the metal ring member, is fixed to the rotatable bearing race. Between the metal ring member and the metal or resin sub-ring member, a gap is defined which constitutes a labyrinth seal structure.

Abstract: A bearing device for a wheel has a hub wheel and a constant velocity universal joint with an outer joint member. Projecting portions extending in an axial direction are provided on one of an outer surface of a shaft section of the outer joint member and an inner surface of a hole portion of the hub wheel. The projecting portions are press-fitted into the other along the axial direction, and recessed portions are formed in the other through press-fitting of the projecting portions. Thus, a recess-projection fitting structure is formed, in which the projecting portions and the recessed portions are held in close contact with each other through an entire region of fitting contact regions therebetween.

Abstract: A rolling bearing includes rolling elements incorporated between an outer race and an inner race, a resin seal ring covering the opening of at least one end of the bearing space, and a filter covering an oil hole formed in the seal ring for capturing foreign matter contained in lubricating oil. The filter and the resin seal ring are integrated by insert molding. The filter and the seal ring are made of the same material. An annular lip portion, which is separate from the seal ring, is in contact with the outer race. An engaged portion provided on the radially inner side of the seal ring is engaged in a recess formed in the inner race such that, during thermal expansion of the seal ring, the engaged portion is engaged such that the seal ring is movable in the radial direction relative to the inner race.

Abstract: A bearing device includes a recess-projection fitting structure in which a hub wheel and a shaft section, which is fitted in a hole of the hub wheel of the outer joint member of the constant velocity universal joint, are unitized together. In the recess-projection fitting structure, entire fitting regions among projections on the outer surface of the shaft section of the outer joint member and recesses, which fit on the projections, are brought into intimate contact with each other.

Abstract: A recess-projection fitting structure includes projections extending in an axial direction on an outer diameter surface of a shaft section of an outer joint member or an inner diameter surface of a hole of a hub wheel, press-fitting the projections in another of the outer diameter surface and the inner diameter surface along the axial direction, and forming recesses brought into contact and fitted with the projections by press fitting in the other of the outer diameter surface and the inner diameter surface, the projections and the recesses being held in contact with each other through intermediation. An outer member is fitted in a hole of a knuckle of a vehicle. Annular grooves are formed respectively in an outer peripheral surface of the outer member and an inner peripheral surface of the hole of the knuckle, and a snap ring is engaged with both the annular grooves.

Abstract: A rolling bearing includes rolling elements incorporated between an outer race and an inner race, a resin seal ring covering the opening of at least one end of the bearing space, and a filter covering an oil hole formed in the seal ring for capturing foreign matter contained in lubricating oil. The filter and the resin seal ring are integrated by insert molding. The filter and the seal ring are made of the same material. An annular lip portion, which is separate from the seal ring, is in contact with the outer race. An engaged portion provided on the radially inner side of the seal ring is engaged in a recess formed in the inner race such that, during thermal expansion of the seal ring, the engaged portion is engaged such that the seal ring is movable in the radial direction relative to the inner race.

Abstract: A seal ring including filters is mounted to a rolling bearing. The bearing includes rolling elements disposed between an outer race and an inner race. The seal ring is made of a resin or a metal and covers an end opening of the bearing space defined between the outer race and the inner race. The filters are detachably fitted in oil flow holes formed in the seal ring. The filters catch foreign matter contained in lubricating oil. The seal ring is engaged by one of the outer race and the inner race. An annular member made of a material softer than the seal ring is fixed to the seal ring. The annular member serves as a lip facing the other of the inner and outer races with a gap left therebetween, or in abutment with the other of the inner and outer races.

Abstract: A rolling bearing is provided wherein one open end of a bearing space formed between an outer race and an inner race is covered with a sealing ring provided with oil flow holes provided with filters. The sealing ring includes engaging portions provided on the sealing ring in a protruding manner along a circumferential direction thereof, and engaged in recesses provided on the inner race. An annular member made of a material softer than that of the sealing ring is fixed to the sealing ring. The annular member includes a lip portion facing the outer race with a gap or kept in contact with the outer race. The sealing ring is formed by injection molding a resin, and weld lines generated during the injection molding are formed in portions of the sealing ring corresponding to radial directions along which the oil flow holes are not disposed.

Abstract: A bearing device for a wheel prevents backlash in a circumferential direction and has excellent workability for connecting a hub wheel and an outer joint member of a constant velocity universal joint. The bearing device includes a recess-projection fitting structure in which the hub wheel and a shaft section, which is fitted in a hole of the hub wheel of the outer joint member of the constant velocity universal joint, are unitized together. In the recess-projection fitting structure, entire fitting regions among projections on the outer surface of the shaft section of the outer joint member and recesses, which fit on the projections, are brought into intimate contact with each other.

Abstract: A rolling bearing includes an outer bearing race and an inner bearing race defining a bearing space therebetween. Rolling elements are mounted in the bearing space. A seal device is provided at one axial opening of the bearing space and includes a ring member formed of a metal and formed with through holes configured such that lubricating oil can pass through the through holes and solid foreign substances cannot pass through the through holes. One of the outer bearing race and the inner bearing race is stationary, and the other is rotatable. The ring member is in engagement with the stationary bearing race. A sub-ring member, which is a separate member from the ring member and made of a metal, is fixed to the rotatable bearing race. Between the ring member and the sub-ring member, a gap is defined which constitutes a labyrinth seal structure.

Abstract: A rolling bearing is provided wherein one open end of the bearing space formed between an outer race and an inner race is covered with a sealing ring provided with oil flow holes provided with filters. The sealing ring includes a plurality engaging portions provided on the sealing ring in a protruding manner along the circumferential direction thereof, and engaged in recesses provided on the inner race. An annular member made of a material softer than that of the sealing ring is fixed to the sealing ring. The annular member includes a lip portion facing the outer race with a gap or kept in contact with the outer race. The sealing ring is formed by injection molding a resin, and weld lines generated during the injection molding are formed in the portions of the sealing ring corresponding to radial directions along which the oil flow holes are not disposed.

Abstract: A bearing device for a wheel prevents backlash in a circumferential direction and has excellent workability for connecting a hub wheel and an outer joint member of a constant velocity universal joint. The bearing device includes a recess-projection fitting structure in which the hub wheel and a shaft section, which is fitted in a hole of the hub wheel of the outer joint member of the constant velocity universal joint, are unitized together. In the recess-projection fitting structure, entire fitting regions among projections on the outer surface of the shaft section of the outer joint member and recesses, which fit on the projections, are brought into intimate contact with each other.

Abstract: A seal ring including filters is mounted to a rolling bearing. The bearing includes rolling elements disposed between an outer race and an inner race. The seal ring is made of a resin or a metal and covers an end opening of the bearing space defined between the outer race and the inner race. The filters are detachably fitted in oil flow holes formed in the seal ring. The filters catch foreign matter contained in lubricating oil. The seal ring is engaged by one of the outer race and the inner race. An annular member made of a material softer than the seal ring is fixed to the seal ring. The annular member serves as a lip facing the other of the inner and outer races with a gap left therebetween, or in abutment with the other of the inner and outer races.

Abstract: A bearing device for a wheel prevents backlash in a circumferential direction and has excellent workability for connecting a hub wheel and an outer joint member of a constant velocity universal joint. The bearing device includes a recess-projection fitting structure in which the hub wheel and a shaft section, which is fitted in a hole of the hub wheel of the outer joint member of the constant velocity universal joint, are unitized together. In the recess-projection fitting structure, entire fitting regions among projections on the outer surface of the shaft section of the outer joint member and recesses, which fit on the projections, are brought into intimate contact with each other.

Abstract: A bearing device for a wheel prevents backlash in a circumferential direction and has excellent workability for connecting a hub wheel and an outer joint member of a constant velocity universal joint. The bearing device includes a recess-projection fitting structure in which the hub wheel and a shaft section, which is fitted in a hole of the hub wheel of the outer joint member of the constant velocity universal joint, are unitized together. In the recess-projection fitting structure, entire fitting regions among projections on the outer surface of the shaft section of the outer joint member and recesses, which fit on the projections, are brought into intimate contact with each other.

Abstract: A bearing device for a wheel prevents backlash in a circumferential direction and has excellent workability for connecting a hub wheel and an outer joint member of a constant velocity universal joint. The bearing device includes a recess-projection fitting structure in which the hub wheel and a shaft section, which is fitted in a hole of the hub wheel of the outer joint member of the constant velocity universal joint, are unitized together. In the recess-projection fitting structure, entire fitting regions among projections on the outer surface of the shaft section of the outer joint member and recesses, which fit on the projections, are brought into intimate contact with each other.