Wheel bearing unit

• US 6,428,214 B2
• Filed: 11/30/2000
• Issued: 08/06/2002
• Est. Priority Date: 01/11/2000
• Status: Active Grant

• Current Assignee: NTN Corporation
• Original Assignee: NTN Corporation
• Inventors: Torii, Akira, Tajima, Eiji
• Primary Examiner(s): Butler, Douglas C.
• Application Number:
  US09/725,505
• Publication Number:
  US 20010007600A1
• Time in Patent Office: 614 Days
• Field of Search: 384/544, 384/499, 384/500, 384/504, 384/505, 384/506, 384/448, 384/510, 384/512, 384/513, 384/515, 384/516, 384/537, 384/545, 384/543, 384/584, 384/585, 384/589, 384/622, 384/490, 298/980.66, 298/980.62, 298/980.63, 298/980.61, 451/52, 280/124.125, 280/103, 280/105, 464/906, 464/132
• US Class Current: 384/544
• CPC Class Codes: B60B 27/00 Hubs non-metallic B60B5/00; of high resiliency B60B9/00
• 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 19/187 with all four raceways integrated on parts other than race rings, e.g. fourth generation hubs
• CPC Class Codes: F16C 2240/40 Linear dimensions, e.g. length, radius, thickness, gap
• CPC Class Codes: F16C 2326/02 Wheel hubs or castors
• CPC Class Codes: F16C 33/585 of raceways, e.g. ribs to guide the rollers
• CPC Class Codes: F16C 33/64 Special methods of manufacture
• CPC Class Codes: Y10T 29/49684 with race making
• CPC Class Codes: Y10T 29/49689 Race making

Abstract

A wheel bearing unit is with an outer race member having two rows of raceway surfaces formed in its inner peripheral surface. In the vicinity of the groove bottom portion of the raceway surface of an inner race member is provided a projection having a diameter greater than the inscribed circle diameter. The raceway surface, the outer peripheral surface of the projection, and smaller end face are concurrently ground to keep within a predetermined range of standard values the radius difference between the diameter of the groove bottom portion of the raceway surface of the inner race member and the outer diameter of the projection, as well as the core deviation between the groove bottom portion and the smaller end face.

Claims

1. A wheel bearing unit comprising:

an outer race member having two rows of raceway surfaces formed in its inner peripheral surface, the outer race member being attached to a body of a motor vehicle; and

an inner race member provided with a wheel mounting flange, the inner race member being rotatably supported through two rows of balls by the outer race member,

wherein the inner race member has a projection formed in vicinity of a groove bottom portion of its raceway surface, the projection having a diameter greater than an inscribed circle diameter,

and wherein, in the inner race member, the raceway surface, an outer peripheral surface of the projection, and a smaller end face are concurrently ground to keep within a predetermined range of standard values a radius difference between a diameter of a groove bottom portion of the raceway surface of the inner race member and an outer diameter of the projection, as well as a core deviation between a groove bottom portion of the raceway surface and the smaller end face.

2. A wheel bearing unit as claimed in claim 1, wherein a highest value of a tolerance of the radius difference between the diameter of the groove bottom portion of the raceway surface of the inner race member and the outer diameter of the projection is limited to 20 μ

m.

3. A wheel bearing unit as claimed in claim 1, wherein a highest value of a tolerance of the core deviation between the groove bottom portion of the raceway surface of the inner race member and the smaller end face is limited to 20 μ

m.

4. A wheel bearing unit as claimed in claim 1,

wherein the inner race member further comprising:

a hub wheel having a wheel mounting flange formed integrally therein; and

an inner ring provided separately from the hub wheel,

wherein the hub wheel has a raceway surface formed so as to face one of two rows of the raceway surfaces of the outer race member, and the inner ring has a raceway surface formed so as to face the other of two rows of the raceway surfaces of the outer race member.

5. A wheel bearing unit as claimed in claim 4, wherein an outer peripheral surface of a shoulder portion of the inner wheel is realized as a ground surface free from lead burrs.

6. A wheel bearing unit as claimed in claim 4, wherein the hub wheel has a sealing land formed so as to extend from a base end portion of the flange through the raceway surface, the sealing land being realized as a ground surface free from lead burrs.

7. A wheel bearing unit as claimed in claim 2,

wherein the inner race member further comprising:

a hub wheel having a wheel mounting flange formed integrally therein; and

an inner ring provided separately from the hub wheel,

wherein the hub wheel has a raceway surface formed so as to face one of two rows of the raceway surfaces of the outer race member, and the inner ring has a raceway surface formed so as to face the other of two rows of the raceway surfaces of the outer race member.

8. A wheel bearing unit as claimed in claim 7, wherein an outer peripheral surface of a shoulder portion of the inner wheel is realized as a ground surface free from lead burrs.

9. A wheel bearing unit as claimed in claim 7, wherein the hub wheel has a sealing land formed so as to extend from a base end portion of the flange through the raceway surface, the sealing land being realized as a ground surface free from lead burrs.

10. A wheel bearing unit as claimed in claim 3,

wherein the inner race member further comprising:

a hub wheel having a wheel mounting flange formed integrally therein; and

an inner ring provided separately from the hub wheel,

wherein the hub wheel has a raceway surface formed so as to face one of two rows of the raceway surfaces of the outer race member, and the inner ring has a raceway surface formed so as to face the other of two rows of the raceway surfaces of the outer race member.

11. A wheel bearing unit as claimed in claim 10, wherein an outer peripheral surface of a shoulder portion of the inner wheel is realized as a ground surface free from lead burrs.

12. A wheel bearing unit as claimed in claim 10, wherein the hub wheel has a sealing land formed so as to extend from a base end portion of the flange through the raceway surface, the sealing land being realized as a ground surface free from lead burrs.