Koyo Seiko Company, Ltd.

Teruyuki Kawatani

Tomohiro Ishii

Nobuyuki Seo

Yasuhiro Miyata

Kenji Takahashi

Kazutoshi Toda

Shinichirou Kashiwagi

Teruyuki Wakisaka

Masahiro Inoue

Tadashi Mitarai

Koichi Shimizu

A fastening structure capable of preventing deterioration in the flatness of a surface of a flange portion () when a serration () of a bolt () is press-fit into the flange portion (). In this fastening structure, one portion in an axial direction of an outer peripheral surface () of the bolt () is provided with the serration (). The bolt () is press-fit into a bolthole () formed through the flange portion () of a mounting member (). The serration () is located apart from respective end surfaces (A) and (B) of the flange portion () by first and second distances (D, C), and the first and second distances (D, C) each exceed 13% of the thickness (A) of the flange portion (). With this arrangement, the serration () presses a bolthole inner peripheral surface () only in the region located far apart from both of the end surfaces (A andB) of the flange portion ().

Fastening structure including a bolt having a serration that is press-fit into a bolthole of a flange

A bearing apparatus includes a hollow shaft provided around an outer peripheral surface with a bearing fitting region, and a rolling bearing having an inner ring fitted around the bearing fitting region of the hollow shaft. A shaft end of the hollow shaft is bent outwardly in a diametrical direction, thereby being caulked on an outer end surface of the inner ring. The bearing fitting region has a hardened layer in a region from a first position corresponding to an inner end surface of the inner ring of the rolling bearing to a second position before a position corresponding to an outer end surface of the inner ring, and has a non-hardened layer in another region from the outer end surface corresponding position of the inner ring to the shaft end. The second position representative of a caulked side end portion of the hardened layer is defined based on a predetermined relational expression.

Bearing apparatus and producing method thereof

A bearing is mounted on a hollow shaft of a hub wheel. A shaft end of the hollow shaft is deformed radially outward and caulked to an outer end face of an inner ring of the bearing. Between a first area in which a spline portion is formed and a second area in which a caulked portion is formed, between a bending starting point for bending the shaft end radially outward and an end face of the shaft end on an inner peripheral face of the hollow shaft, a third area for suppressing deformation of the inner peripheral face of the hollow shaft caused by the caulking is formed. The third area cushions deformation in the first area.

Method for forming a bearing apparatus

A fastening structure capable of preventing deterioration in the flatness of a surface of a flange portion ( ) when a serration ( ) of a bolt ( ) is press-fit into the flange portion ( ). In this fastening structure, one portion in an axial direction of an outer peripheral surface ( ) of the bolt ( ) is provided with the serration ( ). The bolt ( ) is press-fit into a bolthole ( ) formed through the flange portion ( ) of a mounting member ( ). The serration ( ) is located apart from respective end surfaces ( A) and ( B) of the flange portion ( ) by first and second distances (D, C), and the first and second distances (D, C) each exceed 13% of the thickness (A) of the flange portion ( ). With this arrangement, the serration ( ) presses a bolthole inner peripheral surface ( ) only in the region located far apart from both of the end surfaces ( A and B) of the flange portion ( ).

A fastening structure capable of preventing deterioration in the flatness of a surface of a flange portion (,) when a serration (,) of a bolt (,) is press-fit into the flange portion (,). In this fastening structure, one portion in an axial direction of an outer peripheral surface (,) of the bolt (,) is provided with the serration (,). The bolt (,) is press-fit into a bolthole (,) formed through the flange portion (,) of a mounting member (,). The serration (,) is located apart from respective end surfaces (,A),,B) of the flange portion (,) by first and second distances (D, C), and the first and second distances (D, C) each exceed 13% of the thickness (A) of the flange portion (,). With this arrangement, the serration (,) presses a bolthole inner peripheral surface (,) only in the region located far from both end surfaces (,A and,B) of the flange portion (,).

Fastening structure including a bolt having a serration that is press-fit into a bolt hole of a flange

The present invention discloses to a processing method for a shaft for a hub unit comprising a shaft body portion 2 and a radial outward flange 3 provided on one end thereof. The processing method comprises the steps of: machining, on a root portion 5 of the flange 3, an internal diameter surface 7 and a side 8 of an annular portion 6 extending in a direction of axis X--X of the shaft body portion 2 and in a direction opposite to the shaft body portion 2; and clamping the internal diameter surface 7 with the side 8 of the annular portion 6 being a reference, in which clamped state a flange side 9 on the annular portion 5 side and an outer peripheral surface 10 of the shaft body portion are machine-finished.

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Kashiwara, Japan

Teruyuki Kawatani