Abstract: A pair of pre-loaded ball bearings 1, 2 are fixed to a shaft 3 having a flange 3a to be a reference surface Q formed on one end, and where a clearance C is secured between the surface 1c on the flange side of the inner race 1b of the bearing 1 on the side of the flange 3a and the flange surface 3b.

Abstract: Two bearings 3, 4 are used to rotatably support the pivot 1 with reference to a fixed shaft. The swing arm 5 is highly precisely fixed to the pivot 1. The outer diameter 4b of the outer race 4a of the lower bearing 4 is larger than the outer diameter 3b of the outer race 3a of the upper bearing 3. The end surface of the outer race 4b of the outer race 4a of the lower bearing 4 and the outer periphery 3b of the outer race 3a of the upper ball bearing 3 are used as a reference surface to fix the swing arm 5. The housing used in the prior art is eliminated from the structure according to the present invention to reduce the number of parts.

Abstract: A rolling-bearing unit comprising a pair of bearing assembled such that the tolerance range of the radial clearance or contact angle of the ball bearings is divided into a plurality of divisions, and that a pair of ball bearings is selected from the same division, and that a pre-load, which is set according to the division, is applied to the selected pair of ball bearings as they are installed in the unit.

Abstract: Two bearings 3, 4 are used to rotatably support the pivot 1 with reference to a fixed shaft. The swing arm 5 is highly precisely fixed to the pivot 1. The outer diameter 4b of the outer race 4a of the lower bearing 4 is larger than the outer diameter 3b of the outer race 3a of the upper bearing 3. The end surface of the outer race 4b of the outer race 4a of the lower bearing 4 and the outer periphery 3b of the outer race 3a of the upper ball bearing 3 are used as a reference surface to fix the swing arm 5. The housing used in the prior art is eliminated from the structure according to the present invention to reduce the number of parts.

Abstract: The locus of the displacement of the centers of the balls of a ball bearing is made elliptical and the radial bearing rigidity of the ball bearing in one radial direction is made greater than the radial bearing rigidity in another radial direction orthogonal to the one radial direction, or at least one of the axial length of the portion on the outer diametral surface of the inner race of the ball bearing which is fitted to a shaft and the axial length of the portion on the outer diametral surface of the outer race of the ball bearing which is fitted to a housing is made ½ or less of the bearing width of the ball bearing, whereby the radial rigidity of a ball bearing device is made very small as compared with the radial rigidity in the prior art. As a result, the stability of a swing arm system can be enhanced and higher speed and higher accuracy of control become possible.

Abstract: A pair of pre-loaded ball bearings 1, 2 are fixed to a shaft 3 having a flange 3a to be a reference surface Q formed on one end, and where a clearance C is secured between the surface 1c on the flange side of the inner race 1b of the bearing 1 on the side of the flange 3a and the flange surface 3b.

Abstract: A rolling bearing unit for a swing arm comprises a pivot, a pair of rolling bearings for rotatably supporting the pivot with respect to a stationary shaft, and an E block for the swing arm connected to the pivot, the E block having ends at least one of which is provided with an axially extending lip section, and the lip section being bent e.g. at three locations to be crimped against the end of the pivot for connection.

Abstract: The locus of the displacement of the centers of the balls of a ball bearing is made elliptical and the radial bearing rigidity of the ball bearing in one radial direction is made greater than the radial bearing rigidity in another radial direction orthogonal to the one radial direction, or at least one of the axial length of the portion on the inner diametral surface of the inner race of the ball bearing which is fitted to a shaft and the axial length of the portion on the outer diametral surface of the outer race of the ball bearing which is fitted to a housing is made ½ or less of the bearing width of the ball bearing, whereby the radial rigidity of a ball bearing device is made very small as compared with the radial rigidity in the prior art. As a result, the stability of a swing arm system can be enhanced and the higher speed and higher accuracy of control become possible.

Abstract: The locus of the displacement of the centers of the balls of a ball bearing is made elliptical and the radial bearing rigidity of the ball bearing in one radial direction is made greater than the radial bering rigidity in the other radial direction orthogonal to the one radial direction, or at least one of the axial length of the portion on the inner diametral surface of the inner race of the ball bearing which is fitted to a shaft and the axial length of the portion on the outer diametral surface of the outer race of the ball bearing which is fitted to a housing is made ½ or less of the bearing width of the ball bearing, whereby the radial rigidity of a ball bearing device is made greatly small as compared with the radial rigidity in the prior art and as the result, the stability of a swing arm system can be enhanced and the higher speed and higher accuracy of control become possible.

Abstract: A rolling-bearing unit comprising a pair of bearing assembled such that the tolerance range of the radial clearance or contact angle of the ball bearings is divided into a plurality of divisions, and that a pair of ball bearings is selected from the same division, and that a pre-load, which is set according to the division, is applied to the selected pair of ball bearings as they are installed in the unit.

Abstract: The locus of the displacement of the centers of the balls of a ball bearing is made elliptical and the radial bearing rigidity of the ball bearing in one radial direction is made greater than the radial bering rigidity in the other radial direction orthogonal to the one radial direction, or at least one of the axial length of the portion on the inner diametral surface of the inner race of the ball bearing which is fitted to a shaft and the axial length of the portion on the outer diametral surface of the outer race of the ball bearing which is fitted to a housing is made ½ or less of the bearing width of the ball bearing, whereby the radial rigidity of a ball bearing device is made greatly small as compared with the radial rigidity in the prior art and as the result, the stability of a swing arm system can be enhanced and the higher speed and higher accuracy of control become possible.

Abstract: A rolling bearing according to the present invention comprises an inner race 29, an outer race 31 and a plurality of balls 37 disposed therebetween. The inner race 29 has a raceway surface on its outer peripheral surface. The outer race 31 includes a raceway surface on its inner peripheral surface. The balls 37 are rotatably interposed between the raceway surfaces of the inner and outer races. A lubricant is enclosed in a space 41 formed between the raceways of the outer and inner races by an amount of 0.3% to 3% of the capacity of the space.

Abstract: A rolling bearing according to the present invention comprises an inner race 29, an outer race 31 and a plurality of balls 37 disposed therebetween. The inner race 29 has a raceway surface on its outer peripheral surface. The outer race 31 includes a raceway surface on its inner peripheral surface. The balls 37 are rotatably interposed between the raceway surfaces of the inner and outer races. A lubricant is enclosed in a space 41 formed between the raceways of the outer and inner races by an amount of 0.3% to 3% of the capacity of the space.

Abstract: A rolling bearing according to the present invention comprises an inner race 29, an outer race 31 and a plurality of balls 37 disposed therebetween. The inner race 29 has a raceway surface on its outer peripheral surface. The outer race 31 includes a raceway surface on its inner peripheral surface. The balls 37 are rotatably interposed between the raceway surfaces of the inner and outer races. A lubricant is enclosed in a space 41 formed between the raceways of the outer and inner races by an amount of 0.3% to 3% of the capacity of the space.

Abstract: A disc drive device includes a rotational assembly which is adapted to mount a disc thereon and is rotatably driven by a motor. The rotational assembly is rotatably supported on a support assembly by a radial hydrodynamic fluid bearing and a thrust bearing. An axial load is applied to the thrust bearing by a magnetic attractive force of up to 30N and is greater than a dead weight of the rotational assembly.

Abstract: In a spindle motor for a disc drive in which a rotatable body having a disc mounted thereon is rotatively driven by a motor, the rotatable body is rotatably supported on a support member through a ball bearing and a hydrodynamic fluid bearing, and a preload equal to or greater than an axial load of 1N is imparted to the ball bearing.

Abstract: A novel hydro-dynamic fluid bearing device is herein disclosed which comprises a cylindrical shaft, a substantially cylindrical bearing member for axially supporting the shaft rotatably in a cylindrical hole having a bottom surface, a supporting member fixed on one side of the shaft and the bearing member, and a rotation member fixed on the other side of the shaft and the bearing member and rotatably supported on the supporting member, grooves for generating hydro-dynamic fluid being formed on at least one of the outer peripheral surface of the shaft and the inner peripheral surface of the cylindrical hole of the bearing member, wherein the bearing member is made of a resin material, and the outer peripheral surface of the substantially cylindrical portion is fixed to an annular reinforcing member having a higher rigidity than the bearing member.

Abstract: The locus of the displacement of the centers of the balls of a ball bearing is made elliptical and the radial bearing rigidity of the ball bearing in one radial direction is made greater than the radial bearing rigidity in another radial direction orthogonal to the one radial direction, or at least one of the axial length of the portion on the inner diametral surface of the inner race of the ball bearing which is fitted to a shaft and the axial length of the portion on the outer diametral surface of the outer race of the ball bearing which is fitted to a housing is made 1/2 or less of the bearing width of the ball bearing, whereby the radial rigidity of a ball bearing device is made very small as compared with the radial rigidity in the prior art. As a result, the stability of a swing arm system can be enhanced and higher speed and higher accuracy of control become possible.

Abstract: A novel hydro-dynamic fluid bearing device is herein disclosed which comprises a cylindrical shaft, a substantially cylindrical bearing member for axially supporting the shaft rotatably in a cylindrical hole having a bottom surface, a supporting member fixed on one side of the shaft and the bearing member, and a rotation member fixed on the other side of the shaft and the bearing member and rotatably supported on the supporting member, grooves for generating hydro-dynamic fluid being formed on at least one of the outer peripheral surface of the shaft and the inner peripheral surface of the cylindrical hole of the bearing member, wherein the bearing member is made of a resin material, and the outer peripheral surface of the substantially cylindrical portion is fixed to an annular reinforcing member having a higher rigidity than the bearing member.

Abstract: A bearing device includes a housing, a shaft arranged in an inner circumference of the housing, and a pair of bearings arranged between the shaft and the housing, and spaced from each other in an axial direction of the shaft, at least one of the bearings comprising a sleeve inserted in the housing and formed cylindrically. The sleeve has an outer layer portion including an outer cylindrical surface and an inner layer portion including an inner cylindrical surface, the outer layer portion being harder than the inner layer portion, the inner cylindrical surface having a groove for generating dynamic pressure. The sleeve is improved in working accuracy, and the dynamic pressure generating grooves can be formed with ease.