Abstract: It is desired to prevent generation of negative pressure in a bearing space and to prevent entry of foreign matter such as water into a bearing. The bearing includes an inner race (1), an outer race (3), rolling elements (5) disposed between raceways (2 and 4) of the inner and outer races and retained by a retainer (6), and seal assemblies (7) provided at the respective ends of the outer race (3). Each seal assembly (7) includes a seal case (9) fitted on one end of the outer race (3), and an oil seal (11) mounted in the seal case. A check valve (20) is mounted in the seal case (9) and allows only a flow of gas from outside the bearing into the bearing space. A filter (29) is mounted in a flow passage in the check valve and allows passage of gas and prevents passage of liquid and solids.

Abstract: A tapered roller bearing (1) includes an outer race (5). The outer race (5) is formed by pressing a steel plate, instead of conventional turning, to reduce the manufacturing cost of the outer race (5). The outer race (5) includes a flange portion (11) provided at the large-diameter end of the outer race (5), and a cylindrical portion (12) provided at the small-diameter end of the outer race (5). The flange portion (11) and the cylindrical portion (12) of the outer race (5) are brought into engagement with a housing having an inner peripheral surface corresponding in shape to the outer peripheral surface of the outer race (5) so that the tapered roller bearing (1) can be easily mounted to the housing (2).

Abstract: In a sealed rolling bearing for use in an environment where a large amount of water is splashed and the internal pressure of the bearing becomes negative, a ratio of the difference between an outer diameter of a seal sliding contact surface of an inner race and an inner diameter of a seal lip of an elastic seal member in its natural state to a diameter of a roll neck portion (shaft) on which the inner race is fitted is in the range of 0.27 to 0.40%. This provides reduced frictional heat generation of the seal lip and adequate pressing force applied to the seal lip, thus securing excellent seal performance without requiring an additional mechanism, such as a vent to a contact seal.

Abstract: An object of the present invention is to prevent breakup of segments which constitute a split type retainer for a tapered roller bearing, when the tapered roller bearing is being mounted on target equipment, thereby improving operability in the mounting process. A segment for a tapered roller bearing is provided with a predetermined number of posts between a small-diameter-side end fringe which constitutes a small-diameter-side circumferential edge of a split type retainer and a large-diameter-side end fringe which constitutes a large-diameter-side circumferential edge thereof. Pockets are formed between the posts. At least the large-diameter-side end fringe, out of the small-diameter-side end fringe and the large-diameter-side end fringe, is provided with a large-diameter-side engagement piece.

Abstract: An object of the present invention is to prevent breakup of segments which constitute a split type retainer for a tapered roller bearing, when the tapered roller bearing is being mounted on target equipment, thereby improving operability in the mounting process. A segment for a tapered roller bearing is provided with a predetermined number of posts between a small-diameter-side end fringe which constitutes a small-diameter-side circumferential edge of a split type retainer and a large-diameter-side end fringe which constitutes a large-diameter-side circumferential edge thereof. Pockets are formed between the posts. At least the large-diameter-side end fringe, out of the small-diameter-side end fringe and the large-diameter-side end fringe, is provided with a large-diameter-side engagement piece.

Abstract: An object of the present invention is to prevent breakup of segments which constitute a split type retainer for a tapered roller bearing, when the tapered roller bearing is being mounted on target equipment, thereby improving operability in the mounting process. A segment for a tapered roller bearing is provided with a predetermined number of posts between a small-diameter-side end fringe which constitutes a small-diameter-side circumferential edge of a split type retainer and a large-diameter-side end fringe which constitutes a large-diameter-side circumferential edge thereof. Pockets are formed between the posts. At least the large-diameter-side end fringe, out of the small-diameter-side end fringe and the large-diameter-side end fringe, is provided with a large-diameter-side engagement piece.

Abstract: It is desired to prevent generation of negative pressure in the bearing space and to prevent entry of foreign matter such as water into the bearing. A bearing is provided which includes an inner race (1), an outer race (3), rolling elements (5) disposed between raceways (2 and 4) of the inner and outer races and retained by a retainer (6), and seal assemblies (7) provided at the respective ends of the outer race (3). Each seal assembly (7) includes a seal case (9) fitted on one end of the outer race (3), and an oil seal (11) mounted in the seal case. A check valve (20) is mounted in the seal case (9) which allows only a flow of gas from outside the bearing into the bearing space. A filter (29) is mounted in a flow passage in the check valve which allows passage of gas and prevents passage of liquid and solids.

Abstract: The object is to provide a miniature-sized tapered roller bearing that includes an inner race having an inner diameter of not more than 9 mm and that ensures high dynamic load rating. The ratio of the average diameter DRAVE of the tapered rollers 3 to the inner diameter DIi of the inner race 1, i.e. DRAVE/DIi is set to 0.45 to 0.70 to ensure high dynamic load rating with a miniature-sized tapered roller bearing of which the inner race 1 has an inner diameter of not less than 9 mm.

Abstract: A tapered roller bearing is proposed for supporting each of planetary rotary members that rotate about a common axis and their own axes. The tapered roller bearing includes an inner ring spacer provided adjacent to the small-diameter flange of the inner ring. The retainer retaining the tapered rollers in position includes small- and large-diameter annular portions and bridges connecting the two annular portions together. The retainer further includes a disk portion extending radially inwardly from the axially outer end of the small-diameter annular portion, and a third annular portion extending axially outwardly from the radially inner end of the disk portion. The third annular portion has a radially inner guided surface guided by the radially outer guiding surface of the inner ring spacer. A hardened surface layer and a lubricating film are formed on the radially outer guiding surface of the inner ring spacer.

Abstract: A retainer of a ball bearing is provided in which collisions between the retainer and the balls are reduced even though the balls rotate alternately faster and slower than the retainer at short intervals, without reducing the stiffness of bridges of the retainer or without reducing the connecting spaces for connecting portions of the retainer. The retainer has elliptical pockets to define spaces in the rotational direction of the bearing between the pockets and the balls. The spaces account for 4-10%, preferably 6-10%, of the diameter of the balls, thereby reducing collisions between the retainer and the balls even when the balls rotate alternately faster and slower than the retainer at short intervals, without reducing the stiffness of the bridges.

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.