Device for detecting the rotation speed of a rotating element

• US 20040141669A1
• Filed: 02/26/2004
• Published: 07/22/2004
• Est. Priority Date: 02/02/2001
• Status: Active Grant

• Current Assignee: ABet SKF
• Original Assignee: ABet SKF
• Inventors: Landrieve, Franck, Verbe, Olivier
• Granted Patent: US 7,033,080 B2
• Time in Patent Office: Days
• US Class Current: 384/448
• CPC Class Codes: F16C 13/006 Guiding rollers, wheels or the like, formed by or on the outer element of a single bearing or bearing unit, e.g. two adjacent bearings, whose ratio of length to diameter is generally less than one
• CPC Class Codes: F16C 19/06 with a single row or balls
• CPC Class Codes: F16C 2316/30 Articles for sports, games and amusement, e.g. roller skates, toys
• CPC Class Codes: F16C 41/007 Encoders, e.g. parts with a plurality of alternating magnetic poles
• CPC Class Codes: F16C 41/008 Identification means, e.g. markings, RFID-tags; Data transfer means
• CPC Class Codes: G01P 3/443 mounted in bearings bearings F16C
• CPC Class Codes: G01P 3/446 mounted between two axially spaced rows of rolling elements
• CPC Class Codes: G01P 3/487 delivered by rotating magnets

Abstract

The invention relates to a device for detecting the rotation speed of a rotating element supported by at least one external rotating ring with at least one roller bearing. At least one internal non-rotating ring of the roller bearing is solidly connected to a shaft mounted on a support. The inventive device includes a non-rotating sensor adjacent to the roller bearing and a rotating encoder. The encoder is at least partially fixed by magnetization to a flange which is integral to the rotating ring and which is made from a magnetizable material.

Claims

1. Device for detecting the rotation speed of a rotating element (1) supported by at least one rotating outer ring (7) of at least one roller bearing (5), at least one non-rotating inner ring (9) of the roller bearing being fixed to a spindle (16) installed on a support (20), the device including a non-rotating sensor means (31) adjacent to the bearing and a rotating encoder means (30), the encoder means being partially fixed by magnetisation to a side plate (27) fixed to the rotating ring, and made of magnetisable material, characterised in that the encoder means includes at least one magnet (36) extending over part of the side plate located in the radial and circumferential directions and arranged in the immediate vicinity of a face of the side plate oriented towards the sensor means, such that the attraction force between the magnet and the side plate participates in retaining the said encoder means in contact with the said side plate.

2. Device according to claim 1, characterised in that the magnet is in contact with the side plate.

3. Device according to claim 1 or 2, characterised in that the magnet is bonded to the side plate.

4. Device as claimed in any of claims 1 to 3, characterised in that the magnet is embedded in an annular support.

5. Device according to claim 4, characterised in that the annular support is in contact with the side plate.

6. Device according to claim 4 or 5, characterised in that the annular support is bonded onto the side plate.

7. Device as claimed in any of claims 4 to 6, characterised in that the annular support is centred on the wheel.

8. Device as claimed in any of claims 4 to 6, characterised in that the annular support is centred on a portion of the side plate.

9. Device as claimed in any of claims 1 to 8, characterised in that the encoder means comprises an active encoding part and a magnetisation means formed from the same material.

10. Device as claimed in any of claims 1 to 3, characterised in that the magnet is housed in a compartment.

11. Device according to claim 10, characterised in that the compartment is made by insert moulding of a flexible material on the outside face of the side plate.

12. Device according to claim 10 or 11, characterised in that the compartment has a parallelepiped shape.

13. Device as claimed in any of claims 10 to 12, characterised in that the walls of the compartment are approximately perpendicular to a radial plane.

14. Device as claimed in any of claims 10 to 13, characterised in that the walls of the compartment comprise a part that flares outwards to form an entry chamfer (45b), a central part (45a) acting essentially to retain the magnet, and a reverse tapered part (45c) near the bottom of the compartment.

15. Device as claimed in any of claims 1 to 14, characterised in that it comprises a sealing lip formed from a flexible material.

16. Device according to claims 11 to 15, characterised in that it comprises a disk-shaped element made from the said flexible material and with an approximately radial outside face of the encoder means.

17. Device according to claim 16, characterised in that the magnet is flush with the said face or it is set back from it.

18. Device according to claim 16 or 17, characterised in that the disk-shaped element is fixed in a groove in the rotating ring.

19. Device as claimed in any of claims 16 to 18, characterised in that the disk-shaped element has an inside edge forming a dynamic seal between the element and the contact surface of the non-rotating ring, either in friction or with a narrow gap.

20. Device according to claims 10 to 19, characterised in that the magnet is held in place in the compartment partly by a magnetic force and partly by a mechanical force due to clamping in the said compartment.

23. Roller skates, skateboards, scooters and bicycles comprising a detection device as claimed in any of claims 1 to 20.

21. Encoder intended for use on a device for detecting the rotation speed of a wheel (1) supported by at least one rotating outer ring (7) of at least one roller bearing (5), at least one non-rotating inner ring (9) of the roller bearing being fixed to a spindle (16) installed on a support (20), the device including a non-rotating sensor means (31) adjacent to the bearing, and the encoder comprising means for partly fixing it by magnetisation to a side plate (27) made of magnetisable material, characterised in that the encoder means includes at least one magnet (36) extending over part of the side plate located in the radial and circumferential directions and arranged in the immediate vicinity of a face of the side plate oriented towards the sensor means, such that the attraction force between the magnet and the side plate participates in retaining the said encoder means in contact with the said side plate.

22. Encoder according to claim 21, characterised in that it comprises one or several magnets.