WHEEL SUPPORT BEARING ASSEMBLY

• US 20090268998A1
• Filed: 08/07/2007
• Published: 10/29/2009
• Est. Priority Date: 08/08/2006
• Status: Active Grant

• Current Assignee: NTN Corporation
• Original Assignee: NTN Corporation
• Inventors: Hashimoto, Tetsuya, Komori, Kazuo, Kubota, Kazunori, Fujimura, Akira
• Granted Patent: US 8,142,081 B2
• Time in Patent Office: Days
• US Class Current: 384/537
• CPC Class Codes: B60B 27/0005 with ball bearings
• CPC Class Codes: B60B 27/0094 one or more of the bearing races are formed by the hub
• CPC Class Codes: F16C 19/186 with three raceways provided integrally on parts other than race rings, e.g. third generation hubs
• CPC Class Codes: F16C 2326/02 Wheel hubs or castors in general B60B
• CPC Class Codes: F16C 33/60 divided or split, e.g. comprising two juxtaposed rings
• CPC Class Codes: F16C 43/04 Assembling rolling-contact bearings

Abstract

A wheel support bearing assembly includes an outer member, an inner member and double row balls. The inner member includes a hub unit, which has a wheel mounting flange defined in an outer periphery thereof, and an inner ring mounted on the outer periphery of the inboard end of the hub unit. A shoulder is provided in an inner peripheral edge of the inboard end face of the inner ring. A crimped portion, engageable with a stepped face of the shoulder, is provided in the inboard end of the hub unit by diameter expansion. The crimped portion is formed by crimping such diameter expanded portion which is thin walled by providing a hub inner diameter setback in the inner periphery of the inboard end of the hub unit. This thin walled portion is positioned on a side inboardly of the straight line defining a ball contact angle in the inboard raceway surface.

Claims

1. A wheel support bearing assembly, which comprises:

an outer member having an inner periphery formed with double row raceway surfaces;

an inner member having an outer periphery formed with raceway surfaces opposed to those raceway surfaces of the respective rows;

double row balls interposed between those opposed raceway surfaces;

in which the inner member is made up of a hub unit, which has a wheel mounting flange defined in an outer periphery of an outboard end thereof and also has a center bore defined in a center portion thereof, and an inner ring mounted on an inner ring mounting area, which is defined in the outer periphery of the inboard end of the hub unit and is so configured as to represent an annular recess;

in which the raceway surfaces of the respective rows are formed in the hub unit and the inner ring;

in which a shoulder is defined to indent in an inner peripheral edge of an inboard end face of the inner ring;

in which a crimped portion, engageable with an axially oriented stepped face of the shoulder in the inner ring, is provided in the inboard end of the hub unit by diameter expansion; and

in which the crimped portion of the hub unit is formed by crimping such diameter expanded portion which is thin walled by providing a hub inner diameter setback in the inboard end of the hub unit, and this thin walled portion as a whole is positioned on a side inboardly of the straight line defining a ball contact angle in the inboard raceway surface.

2. The wheel support bearing assembly as claimed in claim 1, wherein the raceway surface in the hub unit is hardened by hardening treatment to provide a hardened surface, and the thin walled portion is a non-hardened portion, the inner ring being hardened in its entirety from surface thereof deep into core thereof by means of a hardening treatment.

3. The wheel support bearing assembly as claimed in claim 1, wherein the shoulder in the inner ring has an axial length within the range of 0.25 to 6 mm.

4. The wheel support bearing assembly as claimed in claim 1, wherein the shoulder in the inner ring has a radial depth within the range of 0.25 to 2.5 mm.

5. The wheel support bearing assembly as claimed in claim 1, wherein the crimped portion of the hub unit has an outer diametric surface held in contact with a straight portion of the shoulder in the inner ring, which has a maximum diameter and is a cylindrical surface.

6. The wheel support bearing assembly as claimed in claim 1, wherein the crimped portion of the hub unit has an outer diametric surface held in non-contact with a straight portion of the shoulder in the inner ring, which has a maximum diameter and is a cylindrical surface.