Sealing device for a wheel hub unit

• US 20050135717A1
• Filed: 12/17/2004
• Published: 06/23/2005
• Est. Priority Date: 12/22/2003
• Status: Active Grant

• Current Assignee: ABet SKF
• Original Assignee: ABet SKF
• Inventors: Savarese, Claudio, Vignotto, Angelo, Monetti, Alfredo, Fea, Alberto
• Granted Patent: US 7,153,029 B2
• Time in Patent Office: Days
• US Class Current: 384/484
• CPC Class Codes: F16C 19/386 in O-arrangement
• CPC Class Codes: F16C 2326/02 Wheel hubs or castors
• CPC Class Codes: F16C 33/7813 for tapered roller bearings
• CPC Class Codes: F16C 33/7886 mounted outside the gap between the inner and outer races, e.g. sealing rings mounted to an end face or outer surface of a race
• CPC Class Codes: F16C 41/007 Encoders, e.g. parts with a plurality of alternating magnetic poles

Abstract

Sealing device (1) for a wheel hub unit (2) which is connected to a differential (3) of a vehicle, and which is provided with a contact rolling bearing (9), the sealing device (1) being mounted in order to protect the bearing (9) from a lubricating fluid which is used to lubricate the differential (3), and presenting a first shield (22) which is integral with an outer race (10) of the bearing (9), a second shield (23) which is arranged inside the first shield (22) and which is integral with an inner race (11) of the bearing (9) and which counter-faces the first shield (22) itself, and a dynamic sealing element (24) which is interposed between the first and the second shield (23); a first static sealing element (51) being associated with a terminal border (37) of the shrink-fit portion (33a), and being arranged inside an external relief (60) in order to create a static seal with a box (5) which extends from the differential (3) to the unit (2).

Claims

1. Sealing device (1) (1′

) for a wheel hub unit (2), the wheel hub unit (2) being connected to a differential device (3), and being provided with a contact rolling bearing (9), the sealing device (1) (1′

) being mounted in such a way as to protect the bearing (9) from a lubricating fluid which is used to lubricate the differential (3), and comprising;

a first shield (22) which is provided with a shrink fit portion (33a) which is shrink fit onto an external relief (60) of an outer race (10) of the bearing (9); and

a second shield (23) which is intergral with an inner race (11) of the bearing (9), and which is arranged, in relation to the bearing (9), inside the first shield (22) in order to counter-face the first shield (22) itself,

the sealing device (1) (1′

) being characterised by the fact that is comprises a first static sealing element (51) (51′

), which is associated with a terminal border (37) of the shrink fit portion (33a), and which is arranged inside said external relief (60).

2. Sealing device according to claim 1, characterised by the fact that the said first static sealing element (51) is defined by a sealing race (51), which is mounted inside the external outlet (14) in order to create a static seal with a sealing box (5) which extends from the differential (3) to the wheel hub unit (2), and which is independent in relation to the said terminal border (37).

3. Sealing device according to claim 1, characterised by the fact that the said static sealing device (51′

) is defined by a sealing race (51′

) which is mounted inside the external relief (60) in order to create a static seal with a sealing box (5) which extends from the differential (3) to the wheel hub unit (2), and which is integrated with the said terminal border (37).

4. Sealing device according to claims 3 characterised by the fact that it comprises a second static sealing element (52), which is made of rubber material in order to partially line the first shield (22), and which is interposed between a frontal surface (13) of the outer race (10) and the said shrink fit portion (33a).

5. Sealing device according to claim 1, characterised by the fact that it comprises a dynamic sealing element (24) which is interposed between the first and second shields (22, 23).

6. Sealing device according to claim 1, characterised by the fact that the second shield (23) comprises a shrink fit wall (25) which is made of metal material and which is shrink fit onto the inner race (11), and a support wall (26) which is integral with the shrink fit wall (25) and which supports a cylindrical encoder (27);

the encoder (27) being an integrating part of the device (1) (1′

) for the measurement of an angular speed of the said bearing (9).

7. Sealing device according to claim 6, characterised by the fact that the first shield (22) comprises a stepped wall (33) which is made f metal material, and which is intergral with the outer race (10) by means of the said shrink fit portion (33a), and which is arranged co-axially in relation to the encoder (27), and which is provided with at least one slit (38) which is suitable for being engaged by a reading sensor (39) of a signal which is generated by the encoder (27) itself.

8. Sealing device according to claim 7, characterised b the fact that the first shield (22) comprises a lining (41) which is made of rubber material, and which is arranged in such a way as to totally cover the said slit (38), and which is provided with a base diaphragm (46);

the base diaphragm (46) being used to close the slit (38), and to separate and seal the encoder (27) from the outside of the device (1) (1′

) itself.

9. Sealing device according to claim 4, characterised by the fact that the said diaphragm (46) is suitable for being placed in contact with a reading surface (39a) of a sensor (39) for reading a signal which is generated by the encoder (27).