Abstract: A groove curvature radius ratio Ri of the inner ring raceway groove to a ball diameter is 54% to 58%, a groove curvature radius ratio Ro of an outer ring raceway groove of an outer ring to the ball diameter is 51% to 58%, and Ri?Ro?0 points. At least an inner ring raceway groove of an inner ring has a maximum surface pressure of 4.7 GPa to 6.0 GPa when a sum of permanent deformation amounts of the ball and the inner ring raceway groove at a center of a contact portion between a ball of an angular ball bearing and the inner ring raceway groove is 1/10,000 of the ball diameter. Accordingly, it is possible to provide the angular ball bearing that can reduce the heat generation amount, and that can reduce the damage caused by the external impact load in the stationary state.

Abstract: In an angular ball bearing (10), an outer race (12) has at least one diameter-directional hole (15) that supplies lubricating oil and passes through from the outer circumferential surface to the inner circumferential surface along the diameter direction. In a cross-section taken along the axial direction passing through a center (O) of the ball (13), the axial-directional position of a line extending through a central axis (X) of the diameter-directional hole (15) in the outer circumferential surface of a retainer (14) is located between an intersection position (A), at which an outer circumferential surface (14a) of the retainer (14) and a surface of a ball (13) intersect, and an axial-directional end (B) of a pocket (P).

Abstract: In an angular ball bearing (10), an outer race (12) has at least one diameter-directional hole (15) that supplies lubricating oil and passes through from the outer circumferential surface to the inner circumferential surface along the diameter direction. In a cross-section taken along the axial direction passing through a center (O) of the ball (13), the axial-directional position of a line extending through a central axis (X) of the diameter-directional hole (15) in the outer circumferential surface of a retainer (14) is located between an intersection position (A), at which an outer circumferential surface (14a) of the retainer (14) and a surface of a ball (13) intersect, and an axial-directional end (B) of a pocket (P).

Abstract: When inner diameter side opening portions are projected on an outer circumferential surface of a retainer along extension lines of central lines of radial holes, at least parts of the inner diameter side opening portions of a plurality of radial holes of an outer ring are positioned within an area of two circles formed by connecting each of axial end portions of adjacent pockets of the retainer in an axial direction. When a central line of any one radial hole coincides with a circumferential phase of a center of a ball, any other radial hole is formed such that the projected inner diameter side opening portion is separated from the ball and an inner circumferential surface of the pocket when viewed from the radial direction of the ball bearing, and a central line of the other radial hole overlaps with the pocket when viewed from the axial direction.

Abstract: When inner diameter side opening portions are projected on an outer circumferential surface of a retainer along extension lines of central lines of radial holes, at least parts of the inner diameter side opening portions of a plurality of radial holes of an outer ring are positioned within an area of two circles formed by connecting each of axial end portions of adjacent pockets of the retainer in an axial direction. When a central line of any one radial hole coincides with a circumferential phase of a center of a ball, any other radial hole is formed such that the projected inner diameter side opening portion is separated from the ball and an inner circumferential surface of the pocket when viewed from the radial direction of the ball bearing, and a central line of the other radial hole overlaps with the pocket when viewed from the axial direction.

Abstract: When inner diameter side opening portions are projected on an outer circumferential surface of a retainer along extension lines of central lines of radial holes, at least parts of the inner diameter side opening portions of a plurality of radial holes of an outer ring are positioned within an area of two circles formed by connecting each of axial end portions of adjacent pockets of the retainer in an axial direction. When a central line of any one radial hole coincides with a circumferential phase of a center of a ball, any other radial hole is formed such that at least parts of the projected inner diameter side opening portion overlap with an inner circumferential surface of the pocket when viewed from a radial direction of a ball bearing, and a central line of the other radial hole is separated from a circumferential phase of the center.

Abstract: When inner diameter side opening portions are projected on an outer circumferential surface of a retainer along extension lines of central lines of radial holes, at least parts of the inner diameter side opening portions of a plurality of radial holes of an outer ring are positioned within an area of two circles formed by connecting each of axial end portions of adjacent pockets of the retainer in an axial direction. When a central line of any one radial hole coincides with a circumferential phase of a center of a ball, any other radial hole is formed such that the projected inner diameter side opening portion is separated from the ball and an inner circumferential surface of the pocket when viewed from the radial direction of the ball bearing, and a central line of the other radial hole overlaps with the pocket when viewed from the axial direction.

Abstract: In an angular contact ball bearing (10), an outer ring (12) has at least one radial hole (15) passing through in the radial direction from the outer peripheral surface to the inner peripheral surface of the outer ring (12), and the axial-direction position of an inner-diameter-side opening part of the radial hole (15) is located between the groove bottom of the outer ring (12) and the point of contact between a ball (13) and the outer ring (12), as well as being separated from a contact ellipse between the ball (13) and an outer ring track groove (12a).

Abstract: According to a crown retainer (11) of a ball guide type, a pocket (9) of the retainer (11) has a straight surface (9a) and a tapered surface (9b) where a ball (7) comes into surface contact therewith. A connection point (9c) between the straight surface (9a) and the tapered surface (9b) is on an inner diameter side of an intersection position (I) between an extension plane (F) of a rolling element equatorial plane and a wall surface of the pocket (9). In a two-dimensional cross section passing through centers (O) of a plurality of balls (7), a distance (?P) between the ball (7) and the wall surface of the pocket (9) in the extension plane (F) in a neutral position is smaller than a shortest distance (?T) between the tapered surface (9b) and the ball (7) in a direction perpendicular to a straight line (L).

Abstract: A ball screw device includes: a threaded shaft; a nut; multiple first balls rollably arranged on a helical raceway composed of a helical groove of the threaded shaft and a helical groove of the nut; an inner ring raceway groove formed on an outer circumferential surface of one axial end of the threaded shaft; an outer ring having an outer ring raceway groove that faces the inner ring raceway groove; and multiple second balls rollably arranged between the inner ring raceway groove and the outer ring raceway groove. The ball screw device converts rotation of the threaded shaft into linear motion of the nut through the first balls rolling on the helical raceway while being subjected to a load. The outer ring has a rolling element insertion hole penetrating from its outer circumferential surface to the outer ring raceway groove and a lid configured to cover the rolling element insertion hole. An inner surface of the lid is formed into a concave shape to serve as part of the outer ring raceway groove.

Abstract: Provided is a bearing device (1) wherein an outer ring (12) of an angular contact ball bearing (10) has at least one supply hole (15) for supplying a lubricating oil, and an outer ring spacer (30) comprises, on the inner peripheral surface thereof, a tapered surface (32) which increases in diameter with the distance from an axial end surface (31) contacting the outer ring (12), the outer ring spacer (30) also comprising a discharge hole (34) which passes therethrough in the radial direction and through which the lubricating oil is discharged. Further, the inner diameter dimension (D31) of the axial end surface (31) of the outer ring spacer (30) is set to be equal to or larger than the inner diameter dimension (D12e) of an axial other side end surface (12e) of the outer ring (12) contacting the outer ring spacer (30).

Abstract: When inner diameter side opening portions are projected on an outer circumferential surface of a retainer along extension lines of central lines of radial holes, at least parts of the inner diameter side opening portions of a plurality of radial holes of an outer ring are positioned within an area of two circles formed by connecting each of axial end portions of adjacent pockets of the retainer in an axial direction. When a central line of any one radial hole coincides with a circumferential phase of a center of a ball, any other radial hole is formed such that at least parts of the projected inner diameter side opening portion overlap with an inner circumferential surface of the pocket when viewed from a radial direction of a ball bearing, and a central line of the other radial hole is separated from a circumferential phase of the center.

Abstract: When inner diameter side opening portions are projected on an outer circumferential surface of a retainer along extension lines of central lines of radial holes, at least parts of the inner diameter side opening portions of a plurality of radial holes of an outer ring are positioned within an area of two circles formed by connecting each of axial end portions of adjacent pockets of the retainer in an axial direction. When a central line of any one radial hole coincides with a circumferential phase of a center of a ball, any other radial hole is formed such that the projected inner diameter side opening portion is separated from the ball and an inner circumferential surface of the pocket when viewed from the radial direction of the ball bearing, and a central line of the other radial hole overlaps with the pocket when viewed from the axial direction.

Abstract: An angular contact ball bearing (10) is configured such that: an outer ring (12) thereof includes at least one radial hole (15) that extends radially through the outer ring (12) from an outer circumferential surface thereof to an inner circumferential surface thereof; and when a minor angle formed relative to a rotation axis (s) of a ball (13) by a straight line that connects a center (O) of the ball (13) and an intersection point between a centerline (X) of the radial hole (15) and a surface of the ball (13) is defined as ?, an axial position of the centerline (X) of the radial hole (15) is set to satisfy a relationship of 0°<??60°.

Abstract: In an angular contact ball bearing (10), an outer ring (12) has at least one radial hole (15) passing through in the radial direction from the outer peripheral surface to the inner peripheral surface of the outer ring (12), and the axial-direction position of an inner-diameter-side opening part of the radial hole (15) is located between the groove bottom of the outer ring (12) and the point of contact between a ball (13) and the outer ring (12), as well as being separated from a contact ellipse between the ball (13) and an outer ring track groove (12a)

Abstract: A matched ball bearing includes four or more rows of angular ball bearings axially aligned, two or more rows of the angular ball bearings with contact angles in a same direction being arranged in a back-to-back combination. The respective angular ball bearings have same inner diameters, respectively. The respective angular ball bearings with contact angles in the same direction have same outer diameters, respectively. The respective angular ball bearings with contact angles in different directions have different outer diameters, respectively. With respect to at least the respective angular ball bearings having the larger outer diameters, the angular ball bearing positioned at an axially outboard side has a ball diameter and a contact angle greater than those of the angular ball bearing positioned at an axially inboard side.

Abstract: In an angular ball bearing, an outer ring is provided with a plurality of oil holes. The circumferential phases of the plurality of oil holes are ??45°, when the angular rolling bearing is viewed in the axial direction during rotation of the bearing, when the center of a ball passes through the center line of one oil hole, the ball closest to the remaining oil hole is located at a position which intersects with the center line of the other oil hole, and when an angle formed by a straight line passing through the center of the ball closest to the oil hole and perpendicular to the radial direction of the angular ball bearing, and a tangent at a contact point between the center line of the oil hole and the ball is set as (?) when the angular rolling bearing is viewed from the axial direction.

Abstract: A matched ball bearing includes four or more rows of angular ball bearings axially aligned, two or more rows of the angular ball bearings with contact angles in a same direction being arranged in a back-to-back combination. The respective angular ball bearings have same inner diameters, respectively. The respective angular ball bearings with contact angles in the same direction have same outer diameters, respectively. The respective angular ball bearings with contact angles in different directions have different outer diameters, respectively. With respect to at least the respective angular ball bearings having the larger outer diameters, the angular ball bearing positioned at an axially outboard side has a ball diameter and a contact angle greater than those of the angular ball bearing positioned at an axially inboard side.

Abstract: In an angular ball bearing, an outer ring is provided with a plurality of oil holes. The circumferential phases of the plurality of oil holes are ??45°, when the angular rolling bearing is viewed in the axial direction during rotation of the bearing, when the center of a ball passes through the center line of one oil hole, the ball closest to the remaining oil hole is located at a position which intersects with the center line of the other oil hole, and when an angle formed by a straight line passing through the center of the ball closest to the oil hole and perpendicular to the radial direction of the angular ball bearing, and a tangent at a contact point between the center line of the oil hole and the ball is set as (?) when the angular rolling bearing is viewed from the axial direction.

Abstract: A multiple row combination ball bearing 10 includes at least two rows of ball bearings 11A and 11B. A counterbore 12d is formed on a groove shoulder 12c of an outer ring 12 of the respective ball bearings 11A and 11B. The respective ball bearings 11A and 11B have an inner and outer diameter dimension and a width dimension corresponding to a standard bearing of the ISO standard. An extension line L of a contact angle ? of the ball bearing 11A passes through an axial direction end plane 12e of the ball bearing 11B which is adjacent to the ball bearing 11A at one side in the axial direction. The extension line L of the contact angle ? of the adjacent ball bearing 11B passes through the axial direction end plane 13e of the ball bearing 11A.