Abstract: To avoid a difficulty of inserting a spline shaft into a spline hole, respective holding members 29 constituting a holding device 28 for holding a hub 3 are displaced in a radial inward direction of a small diameter stepped portion 15. The inner peripheral surface of the inside end of an original hole 25 is elastically deformed radially inward the same as or slightly greater than the elastic deformation caused by externally securing tightly an inner ring to the small diameter stepped portion 15. In this condition, a female spline portion for constituting a spline hole is formed in the original hole 25.

Abstract: Upon assembling a hub unit, an inner race element is press-fitted onto a small diameter stepped portion of the hub, and thereafter an inner periphery of an axially extended hole of the hub is subjected to broaching to form a female serration extended in the axial direction, thereby providing a complete product.

Abstract: In a manufacturing method and a manufacturing apparatus for a wheel-support rolling bearing unit, when forming a crimped portion 14 on an end (inside end) of a hub main body 8a, by rocking die forging using a die 26, while preventing enlargement of equipment, in order to prevent forming indentations in a second outer raceway 6a and a second inner raceway 12a, in the present invention, the outer ring 1a is turned by a motor 48, and the balls 32 are rotated. A difference is provided between the rotation speed of the balls 32 and an oscillation speed of the die 26. This difference is preferably at least 10 min?1. By rotating the balls 32 the formation of indentations in the second outer raceway 6a and the second inner raceway 12a is prevented. Moreover, by providing the difference between the rotation speed and the oscillation speed of the die 26, an increase in the torque required for rotation the outer ring 1a is suppressed.

Abstract: In a method of processing a female spline of a hub unit for supporting a wheel, a hole 3a which is formed to be cylindrical is provided on a shaft portion 3c of a hub unit 103 before plastically deforming by caulking (or clinching), and after the plastically deforming by caulking (or clinching), a female spline is formed on the hole 3a by semi-dry or dry broaching. The hole 3a which is formed to be cylindrical after plastically deforming by caulking (or clinching) has the form that the size is greater at a portion nearer a portion 3d plastically deforming by caulking (or clinching) of the shaft portion 3c for an estimated amount of contraction caused by the plastically deforming by caulking (or clinching) or the press-fitting of an inner race element.

Abstract: It's an object of the invention to precisely match a mounting surface 14 of a mounting flange 13 for fixedly supporting a rotor, with a virtual plane perpendicular to the rotation axis of a hub 8b, to thereby prevent judder which occurs at the time of braking. For that purpose, a processing jig is pressed into the inner peripheral surface of an unfinished hole formed in the mounting flange 13 to form female serrations and make mounting holes 15, after which the mounting surface 14 is subjected to finishing. Then a male serration portion 16 of a stud 9 is loosely fitted into the mounting hole 15. As a result, deterioration of the accuracy of the mounting surface 14 accompanying fitting of the male serration portion 16 can be prevented.

Abstract: To avoid a difficulty of inserting a spline shaft into a spline hole, respective holding members 29 constituting a holding device 28 for holding a hub 3 are displaced in a radial inward direction of a small diameter stepped portion 15. The inner peripheral surface of the inside end of an original hole 25 is elastically deformed radially inward the same as or slightly greater than the elastic deformation caused by externally securing tightly an inner ring to the small diameter stepped portion 15. In this condition, a female spline portion for constituting a spline hole is formed in the original hole 25.

Abstract: In a manufacturing method and a manufacturing apparatus for a wheel-support rolling bearing unit, when forming a crimped portion 14 on an end (inside end) of a hub main body 8a, by rocking die forging using a die 26, while preventing enlargement of equipment, in order to prevent forming indentations in a second outer raceway 6a and a second inner raceway 12a, in the present invention, the outer ring 1a is turned by a motor 48, and the balls 32 are rotated. A difference is provided between the rotation speed of the balls 32 and an oscillation speed of the die 26. This difference is preferably at least 10 min?1. By rotating the balls 32 the formation of indentations in the second outer raceway 6a and the second inner raceway 12a is prevented. Moreover, by providing the difference between the rotation speed and the oscillation speed of the die 26, an increase in the torque required for rotation the outer ring 1a is suppressed.

Abstract: A cylindrical portion formed in the inside end portion of the hub is caulked and spread using a pressing mold assembled to an oscillating/caulking apparatus to thereby form the caulking portion. In working or forming the caulking portion, a cylindrical projecting portion formed in the central portion of the leading end face of the pressing mold is inserted into the cylindrical portion to thereby prevent the inside diameter of the cylindrical portion from reducing excessively.

Abstract: When a shape of the cylindrical portion (8b) to be formed into the calking portion (9b) is devised and when a sectional shape of the annular recess portion (23) of the die (15a) for plastically deforming the cylindrical portion (8b) is devised, the calking portion (9b) is continuously given a compressive average stress during the process of working.

Abstract: When a shape of the cylindrical portion (8b) to be formed into the calking portion (9b) is devised and when a sectional shape of the annular recess portion (23) of the die (15a) for plastically deforming the cylindrical portion (8b) is devised, the calking portion (9b) is continuously given a compressive average stress during the process of working.

Abstract: While rotating a spindle 34, the circular hole 15 is worked using a cutting tool 39. Before or after the working operation of the circular hole 15, a chuck 36 is translated in a direction perpendicular to the rotation center axis of the spindle 34 by a slider 35. And, the flat surface 29 as well as the stepped surfaces 31, 31 and inner surfaces 38, 38, which are respectively composed of partially tubular surfaces, are cut or worked.

Abstract: A cylindrical portion formed in the inside end portion of the hub is caulked and spread using a pressing mold assembled to an oscillating/caulking apparatus to thereby form the caulking portion. In working or forming the caulking portion, a cylindrical projecting portion formed in the central portion of the leading end face of the pressing mold is inserted into the cylindrical portion to thereby prevent the inside diameter of the cylindrical portion from reducing excessively.

Abstract: As a ball for ball bearing there is provided a ceramics-coated ball made of a steel having almost the same linear thermal expansion coefficient as that of the bearing ring of the ball bearing and coated with a ceramics material. In this arrangement, even when the temperature during bearing assembly and the working temperature differs from each other, the release of preload or excessive preload can be prevented as in ceramics ball because the bearing and the ball can expand or shrink in the same manner. Further, since the ball and the bearing ring contact with each other via the ceramics layer, fretting abrasion can be prevented, making it possible to obtain excellent running performance and acoustic properties.

Abstract: While rotating a spindle 34, the circular hole 15 is worked using a cutting tool 39. Before or after the working operation of the circular hole 15, a chuck 36 is translated in a direction perpendicular to the rotation center axis of the spindle 34 by a slider 35. And, the flat surface 29 as well as the stepped surfaces 31, 31 and inner surfaces 38, 38, which are respectively composed of partially tubular surfaces, are cut or worked.