Rolling bearing unit with a rotating speed measuring device

• US 6,323,640 B1
• Filed: 01/15/1999
• Issued: 11/27/2001
• Est. Priority Date: 01/16/1998
• Status: Expired due to Term

• Current Assignee: SKF Industrie SPA (ABet SKF)
• Original Assignee: SKF Industrie SPA (ABet SKF)
• Inventors: Forestiero, Daniele, Vignotto, Angelo
• Primary Examiner(s): SNOW, WALTER E
• Application Number:
  US09/232,335
• Time in Patent Office: 1,047 Days
• Field of Search: 324/173, 324/174, 324/207.25, 324/207.22, 384/448
• US Class Current: 324/174
• CPC Class Codes: F16C 19/185 with two raceways provided integrally on a part other than a race ring, e.g. a shaft or housing
• CPC Class Codes: F16C 2326/02 Wheel hubs or castors in general B60B
• CPC Class Codes: F16C 33/7879 with a further sealing ring
• CPC Class Codes: F16C 41/007 Encoders, e.g. parts with a plurality of alternating magnetic poles
• CPC Class Codes: G01P 3/443 mounted in bearings bearings F16C

Abstract

A rolling bearing unit for the hub of a vehicle wheel has an outer rotating race (10), a radially inner stationary race (11), a sealing device (16) between the races (10, 11), and a device for measuring the rotating speed of the outer race (10). The measuring device has an encoder wheel (13) in the form of a radially oriented annular disc of magnetised plastic or rubber material. The rolling bearing has a metallic annular insert (14) adapted for fixing the encoder wheel (13) to the outer race (10); the insert (14) forms: an outer cylindrical portion (14a) for forcefully fitting to an outer surface (10a) of the outer race (10); a radial wall portion (14b, 14d) that concurs in forming an annular seat for accommodating the encoder wheel, and that extends radially inwardly so as to co-operate with the sealing device (16) to close the gap between the races (10, 11); and a joining portion (14c) between the outer cylindrical portion (14a) and the radial wall portion (14b, 14d), on which an axial thrust is applied for performing the force fitting.

Claims

1. A rolling bearing unit for a hub of a vehicle wheel, the bearing comprising:

a radially outer rotating race;

a radially inner stationary race;

a sealing device positioned between said races; and

a measuring device for measuring the rotating speed of the outer race, said measuring device comprising an encoder wheel comprising a radially oriented annular disc of magnetized plastic or rubber material;

the bearing further comprising a metallic annular insert adapted for fixing the encoder wheel to the bearing outer race, said insert comprising;

an outer cylindrical portion that attaches via a force fit to an outer surface of the outer race;

a radial wall portion that forms an annular seat for accommodating the encoder wheel, said wall portion extending radially inwardly so as to co-operate with said sealing device to close the gap between said races; and

a portion joining said outer cylindrical portion and said radial wall portion, said joining portion being a surface on which an axial thrust is applied for performing said force fitting;

wherein the surface on which said axial thrust is applied has an elbow portion joining said outer cylindrical portion to said radial wall portion.

2. The bearing unit of claim 1, wherein said encoder wheel is vulcanized in said seat of the insert.

3. The bearing unit of claim 1, wherein said annular seat has an axial dimension exceeding an axial dimension of the encoder wheel.

4. The bearing unit of claim 1, wherein at least a part of the radial wall portion abuts against a radially outwardly directed extension of a rubber lip of the sealing device.

5. The bearing unit of claim 1, wherein said radial wall portion covers an axially outer side of the encoder wheel.

6. The bearing unit of claim 5, wherein the encoder wheel is separately magnetized before being connected to the insert and elastically yieldable means are axially provided at an interface between the encoder wheel (13) and a surface against which the encoder wheel abuts, to rotationally lock the encoder wheel in relation to the outer race of the bearing unit.

7. The bearing unit of claim 6, wherein said elastically yieldable means are defined by at least one of bumps and grooves obtained in at least one of the encoder wheel, a radial wall of a metallic shield of the sealing device, or a radially outwardly directed extension of a rubber lip of the sealing device.

8. The bearing unit of claim 5, wherein at least a portion of an axially inner side of the encoder wheel abuts against a radially outwardly directed extension of a rubber lip of the sealing device.

9. The bearing unit of claim 5, wherein the insert comprises non-magnetic metal.

10. The bearing unit of claim 1, wherein said radial wall of the insert continues in a radially inner direction towards a non-rotating annular shield of the sealing unit to define, together with the sealing device, a labyrinth seal.

11. A rolling bearing unit for a hub of a vehicle wheel, the bearing comprising:

a radially outer rotating race;

a radially inner stationary race;

a sealing device positioned between said races; and

a measuring device for measuring the rotating speed of the outer race, said measuring device comprising an encoder wheel comprising a radially oriented annular disc of magnetized plastic or rubber material;

the bearing further comprising a metallic annular insert adapted for fixing the encoder wheel to the bearing outer race, said insert comprising;

an outer cylindrical portion that attaches via a force fit to an outer surface of the outer race;

a radial wall portion that forms an annular seat for accommodating the encoder wheel, said wall portion extending radially inwardly so as to co-operate with said sealing device to close the gap between said races; and

a portion joining said outer cylindrical portion and said radial wall portion, said joining portion being a surface on which an axial thrust is applied for performing said force fitting;

wherein the encoder wheel is separately magnetized before being connected to the insert and wherein elastically yieldable means are axially provided at an interface between the encoder wheel and a surface against which the encoder wheel abuts, to rotationally lock the encoder wheel in relation to the outer race of the bearing unit.

12. A rolling bearing unit for a hub of a vehicle wheel, the bearing comprising:

a radially outer rotating race;

a radially inner stationary race;

a sealing device positioned between said races; and

a measuring device for measuring the rotating speed of the outer race, said measuring device comprising an encoder wheel comprising a radially oriented annular disc of magnetized plastic or rubber material;

the bearing further comprising a metallic annular insert adapted for fixing the encoder wheel to the bearing outer race, said insert comprising;

an outer cylindrical portion that attaches via a force fit to an outer surface of the outer race;

a radial wall portion that forms an annular seat for accommodating the encoder wheel, said wall portion extending radially inwardly so as to co-operate with said sealing device to close the gap between said races; and

a portion joining said outer cylindrical portion and said radial wall portion, said joining portion being a surface on which an axial thrust is applied for performing said force fitting;

wherein the encoder wheel is separately magnetized before being connected to the insert and wherein elastically yieldable means are axially provided at an interface between the encoder wheel and a surface against which the encoder wheel abuts, to rotationally lock the encoder wheel in relation to the outer race of the bearing unit;

wherein said elastically yieldable means are defined by at least one of bumps or grooves obtained in at least one of the encoder wheel, a radial wall of a metallic shield of the sealing device, or a radially outwardly directed extension of a rubber lip of the sealing device.