Abstract: In the ball bearing, the ratio of the radius of curvature of an inner race raceway 4 to the outside diameter of balls 8, 8 is set in the range of 0.51 to 0.54. Also, the ratio of the radius of curvature of an outer race raceway 6 to the outside diameter of balls 8, 8 is set in the range of 0.54 to 0.56. Further, an interior geometric clearance c is set at 13 &mgr;m or less. Thanks to these specifications, the balls 8, 8 can be prevented from running up onto the edge of the outer race raceway 6.

Abstract: In the ball bearing, the ratio of the radius of curvature of an inner race raceway 4 to the outside diameter of balls 8, 8 is set in the range of 0.51 to 0.54. Also, the ratio of the radius of curvature of an outer race raceway 6 to the outside diameter of balls 8, 8 is set in the range of 0.54 to 0.56. Further, an interior geometric clearance c is set at 13 &mgr;m or less. Thanks to these specifications, the balls 8, 8 can be prevented from running up onto the edge of the outer race raceway 6.

Abstract: When an information provision program is implemented, an input screen is displayed on a display section (step 101). A specific designation number is input (step 103), and one or plural bearing performance indexes are selected (step 107). When bearing performance indexes are selected, bearing service conditions which are required depending on the bearing performance indexes are input. Then, performance calculation programs corresponding to selected bearing performances are activated (steps 110-1, 110-2, . . .), and obtained calculation results are simultaneously displayed.

Abstract: In the toroidal type continuously variable transmission system 100 incorporating a power roller bearing 11 therein, race grooves 15 and 16 respectively formed in the inner and outer races 35 and 13 of the power roller bearing 11 are respectively structured in such a manner as to have an arc-shaped cross section, and the radii of curvatures of the arc-shaped cross sections of race grooves 15 and 16 are set in the range of 52% to 59% of diameter of a rolling ball body which can roll on these race grooves, thereby being able not only to restrict an increase in dynamic torque of the power roller bearing but also to improve life of the power roller bearing.

Abstract: In a toroidal-type continuously variable transmission, there is provided a thrust rolling bearing interposed between a power roller and a trunnion for supporting a thrust-direction load applied to the power roller. The thrust rolling bearing includes a plurality of rolling elements and a retainer rollably holding the plurality of rolling elements. The retainer defines a circular-ring-shaped main body and a plurality of pockets respectively formed in the main body for rollably holding the plurality of rolling elements. A clearance between the pocket and the rolling element is set in the range of 0.6 to 6.0% of the ball diameter of the rolling element.

Abstract: A ball bearing 36 supports a rotor 35 of an electromagnetic clutch 31 in such a manner that the rotor 35 can be rotated about the axis of the ball bearing 36. The ball bearing 36 includes an outer race 12, an inner race 13, a ball 14, and a retainer 15. The outer and inner races 12 and 13 are each formed in a circular-ring shape. The ball 14 is rollingably interposed between the outer and inner races 12 and 13. In the inner peripheral surface 16 and outer peripheral surface 17 of the outer and inner races 12 and 13, there are respectively formed grooves 12a and 13a each of which extends along the race peripheral direction and has an arc-shaped section. The grooves 12a and 13a are each formed in such a range in which their respective radii of curvature re and ri satisfy 1.0≦(re+ri)/Da≦0.9746 (Da/dm)−0.0304, where Da: the diameter of the ball, and dm: the mean value of the diameters of the inner and outer races of the ball bearing.

Abstract: A power roller for a toroidal type continuous variable transmission system comprises a trunnion having a central shaft, a bearing outer race connected to the trunnion, one face of which is provided with a first track groove concentric with the central shaft, a power roller rotatably mounted on one end portion of the central shaft, the power roller having a face opposing to the one face of the bearing outer race, the face being provided with a second track groove concentric with the central shaft, a plurality of rolling elements retained between the bearing outer race and the power roller and capable of rotating within a track formed by the first track groove and the second track groove, and a disk-like cage coaxially disposed between the bearing outer race and the power roller and rotatable about the central shaft, the cage including a plurality of through pockets for accommodating the rolling elements therein so as to retain the rolling elements within the track, the pockets being arranged at regular interva

Abstract: In the angular contact ball bearing, the respective conditions of the inner race dimensions are designed most suitably to prevent the shoulder portion of the inner race from being opened outwardly, thereby being able to prevent a slipping phenomenon from occurring between the inner race and shaft.

Abstract: Each of the power rollers incorporated in a toroidal-type continuously variable transmission is arranged to prevent damage such as cracks, from being created thereon when the transmission is in operation. The inner circumferential surface of each power roller is configured continuously with a smaller diametral section close to the outer edge surface, a larger diametral section on its opposite side, and a stepping portion connecting them. A needle bearing for supporting the power roller on a displacement shaft is provided inside the larger diametral section. Due to the portion of the smaller diametral section thus provided, the stress capacity is increased with respect to the tensile stresses exerted at the time of operation; thus preventing damage such as cracks, from being easily created.