ROLLING BEARING UNIT WITH ENCODER FOR SUPPORTING WHEEL

• US 20130209016A1
• Filed: 02/07/2011
• Published: 08/15/2013
• Est. Priority Date: 07/22/2010
• Status: Active Grant

• Current Assignee: NSK Limited
• Original Assignee: NSK Limited
• Inventors: Nagano, Masato, Inohae, Jyunya, Kaneko, Yoshio
• Granted Patent: US 8,882,358 B2
• Time in Patent Office: Days
• US Class Current: 384/446
• CPC Class Codes: B60B 2380/12 Ball bearings
• CPC Class Codes: B60B 2380/73 Double track
• CPC Class Codes: B60B 27/0005 with ball bearings
• CPC Class Codes: B60B 27/0068 the element being a sensor
• CPC Class Codes: B60B 27/0073 characterised by sealing means
• CPC Class Codes: B60B 2900/325 Reliability
• CPC Class Codes: B60B 2900/3312 during regular use
• CPC Class Codes: B60B 35/02 Dead axles, i.e. not transmitting torque
• CPC Class Codes: B60B 7/0013 Hub caps
• CPC Class Codes: B60Y 2200/11 Passenger cars; Automobiles
• 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 2240/30 Angles, e.g. inclinations
• CPC Class Codes: F16C 2240/40 Linear dimensions, e.g. length, radius, thickness, gap
• CPC Class Codes: F16C 2240/60 Thickness, e.g. thickness of coatings
• CPC Class Codes: F16C 2326/02 Wheel hubs or castors
• CPC Class Codes: F16C 33/723 Shaft end sealing means, e.g. cup-shaped caps or covers
• CPC Class Codes: F16C 33/768 between relatively stationary parts, i.e. static seals
• 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
• CPC Class Codes: G01P 3/487 delivered by rotating magnets

Abstract

Construction is achieved that is able to prevent strain deformation in the axial direction of a flat plate section 21 of a cover 19a when a cylinder section 20 of the cover 19a, which covers the opening on the inside end in the axial direction of an internal space where an encoder 1 is located, is fitted into and fastened to the inside end section in the axial direction of an outer ring 7. A non-contact section 26a is formed all the way around the inside end section in the axial direction of the cylinder section 20 such that the outer diameter is smaller than the inner diameter of the inside end section in the axial direction of the outer ring, and the dimension L₂₆ in the axial direction is two times or more the thickness dimension t₁₉ of a plate member of the cover 19a. With the cover 19a fitted into the inside end section in the axial direction of the outer ring 7, only the portion of the cylinder section 20 that is nearer the outside in the axial direction than the non-contact section 26a is substantially fitted into the inside end section in the axial direction of the outer ring 7 with an interference fit.

Claims

1. A rolling bearing unit with an encoder for supporting a wheel, comprising:

an outer ring having double-row outer ring raceways around the inner circumferential surface thereof, and that is supported by and fastened to a suspension during use so as not to rotate;

a hub having double-row inner ring raceways around the outer circumferential surface thereof, and with a wheel supported by and fastened thereto during use, rotates together with the wheel;

rolling elements that are provided such that there are a plurality of rolling elements located in each row between the outer ring raceways and the inner ring raceways;

an encoder that is supported by and fastened to the hub so as to be concentric with the hub, with the inside surface in the axial direction thereof being a detected surface having a magnetic characteristic that alternately changes in the circumferential direction; and

a cover that is made of a non-magnetic plate material, and that comprises a cylinder section that extends in the axial direction, and a flat plate section that is bent and extends inward in the radial direction from the inside end section in the axial direction of the cylinder section, and together with this cylinder section fitting into the inside end section in the axial direction of the outer ring, the flat plate section closely facing the detected surface of the encoder;

a non-contact section being formed all the way around the inside end section in the axial direction of the cylinder section of the cover so as not to come in contact with the inner circumferential surface of the outer ring when the cover is fitted inside and fastened to the outer ring, and with the cover fitted into the inside end section in the axial direction of the outer ring, the cylinder section fitting into the inside end section in the axial direction of the outer ring so that only the portion further on the outside in the axial direction than the non-contact section fits inside with an interference fit.

2. The rolling bearing unit with an encoder for supporting a wheel according to claim 1, wherein the non-contact section is formed into a partial conical cylindrical shape that is inclined in a direction such that the diameter becomes smaller going inward in the axial direction.

3. The rolling bearing unit with an encoder for supporting a wheel according to claim 1, wherein the non-contact section is constructed by a small-diameter stepped section with a stepped section being located between the small-diameter stepped section and the portion near the outside in the axial direction.

4. The rolling bearing unit with an encoder for supporting a wheel according to claim 1, wherein the inside end surface in the axial direction of the outer ring protrudes inward in the axial direction more than the inside end surface of the flat plate section.

5. The rolling bearing unit with an encoder for supporting a wheel according to claim 1, wherein a gap between the detected surface of the encoder and the outside surface in the axial direction of the flat plate section of the cover that faces the detected surface of the encoder is larger than a gap between the outside end surface in the axial direction of the cylinder section of the cover and an inside surface in the axial direction of a counterbore which is formed further near the inside end in the axial direction than the outer ring raceway of the outer ring and faces the outside end surface in the axial direction of the cylinder section of the cover.

6. The rolling bearing unit with an encoder for supporting a wheel according to claim 1, wherein a gap between the detected surface of the encoder and the outside surface in the axial direction of the flat plate section of the cover that faces the detected surface of the encoder is larger than a gap between the inside end surface in the axial direction of the hub and the outside surface in the axial direction of the cover that faces the inside end surface in the axial direction of the hub.