Wheel speed sensor

• US 8,237,431 B2
• Filed: 07/07/2008
• Issued: 08/07/2012
• Est. Priority Date: 07/05/2007
• Status: Active Grant

• Current Assignee: Brian Schneider, Jens Anton Heim, Jon Hamilton, Kelly Possehl, Matt Leroy, Terry Fruehling, Tyler Kulig
• Original Assignee: Brian Schneider, Jens Anton Heim, Jon Hamilton, Kelly Possehl, Matt Leroy, Terry Fruehling, Tyler Kulig
• Inventors: Fruehling, Terry, Possehl, Kelly, Schneider, Brian, Leroy, Matt, Kulig, Tyler, Hamilton, Jon, Heim, Jens Anton
• Primary Examiner(s): LEDYNH, BOT L
• Application Number:
  US12/168,655
• Publication Number:
  US 20090051349A1
• Time in Patent Office: 1,492 Days
• Field of Search: 324/173, 324/207.25
• US Class Current: 324/207.25
• CPC Class Codes: F16C 19/06 with a single row or balls
• CPC Class Codes: F16C 2326/20 Land vehicles in general B62
• CPC Class Codes: F16C 33/7859 with a further sealing element
• CPC Class Codes: F16C 33/7896 with two or more discrete sealings arranged in series
• 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

A speed sensor assembly includes a bearing having a first race, a second race, a plurality of ball bearings separating the first race from the second race, and a tone wheel coupled to the second race. The speed sensor assembly also includes a spacer abutting the first race and a sensor positioned adjacent the tone wheel.

Claims

1. A rotation sensor assembly, comprising:

a bearing including;

a first race having an outer edge,

a second race,

a plurality of ball bearings positioned between the first race and the second race,

a carrier coupled to the second race and constructed of a material having a relatively high permeability, and

a tone wheel coupled to the carrier, the tone wheel including a plurality of magnetic pole pairs distributed around a circumference of the tone wheel;

a spacer abutting the first race;

a sensor mounted to the spacer and positioned adjacent the tone wheel, wherein the sensor is configured to sense rotation of the tone wheel relative to the sensor by sensing the magnetic pole pairs during said rotation; and

a flinger press fit onto one of the first race and the second race, the flinger positioned between the tone wheel and the sensor and sealing the carrier and the tone wheel within the bearing,

wherein the carrier is press fit onto the second race such that the tone wheel is at a fixed depth from an outer edge of the first race, the tone wheel having a relative flatness of 0.1 mm, and a distance between the sensor and the tone wheel is fixed at approximately 1.87 mm+/−

0.27 mm.

2. The rotation sensor assembly of claim 1, wherein a portion of the flinger directly adjacent both the tone wheel and the sensor is straight, and the flinger is constructed of a material having a relatively low permeability.

3. The rotation sensor assembly of claim 1, wherein the first race is a stationary inner race and the second race is a rotating outer race, and wherein the tone wheel rotates with the second race and the sensor is stationary.

4. The rotation sensor assembly of claim 1, wherein the sensor is a magnetoresistive sensor.

5. The rotation sensor assembly of claim 1, wherein the sensor is configured to provide a square-wave current output indicative of a rotational speed of the second race.

6. The rotation sensor assembly of claim 1, wherein a distance between the tone wheel and the sensor is controlled by the spacer and the first race, the spacer and first race being machined parts capable of achieving extremely tight tolerances enabling a distance between the sensor and the tone wheel to be highly accurate when the spacer is abutted against the first race.

7. The rotation sensor assembly of claim 1, further comprising a controller connected to the sensor and receiving output from the sensor, wherein the controller is configured to use the output of the sensor to perform at least one of (1) determining a rotational speed of the bearing and (2) detecting a presence or absence of rotation of the bearing.

8. A bearing assembly for use with a speed sensor assembly, comprising:

a first race having an outer edge;

a second race having an outer edge;

a plurality of ball bearings positioned between the first race and the second race, the ball bearings positioned inwardly of the outer edges of the first race and the second race; and

a tone wheel coupled to the second race, the tone wheel including a plurality of magnetic pole pairs distributed around a circumference of the tone wheel,

wherein the entire tone wheel is positioned inwardly of the outer edge of the second race, such that a space is defined between the tone wheel and the outer edge of the second race, and

wherein the tone wheel is positioned at a fixed depth from the outer edge of the first race, the tone wheel having a relative flatness of 0.1 mm, and a distance between the sensor and the tone wheel is fixed at approximately 1.87 mm+/−

0.27 mm.

9. The bearing assembly of claim 8, wherein the entire tone wheel is positioned inwardly of the outer edges of both the first race and the second race such that a space is defined between the tone wheel and the outer edges of the first race and the second race.

10. The bearing assembly of claim 8, further comprising a flinger coupled to one of the first race and the second race and positioned between the tone wheel and the outer edge of the second race.

11. The bearing assembly of claim 10, wherein a portion of the flinger directly adjacent both the tone wheel and the sensor is straight, and the flinger is constructed of a material having a relatively low permeability.

12. The bearing assembly of claim 8, further comprising a carrier coupled to the second race and constructed of a material having a relatively high permeability, the tone wheel being connected to the carrier to couple the tone wheel to the second race.

13. A rotation sensor assembly comprising the bearing assembly of claim 8 and a sensor positioned adjacent the tone wheel and configured to detect rotation of the tone wheel.

14. A rotation sensor assembly, comprising:

a bearing including;

a first race having an outer edge,

a second race,

a plurality of ball bearings positioned between the first race and the second race,

a carrier coupled to the second race and constructed of a material having a relatively high permeability, and

a tone wheel coupled to the carrier, the tone wheel including a plurality of magnetic pole pairs distributed around a circumference of the tone wheel;

a spacer abutting the first race; and

a sensor mounted to the spacer and positioned adjacent the tone wheel, wherein the sensor is configured to sense rotation of the tone wheel relative to the sensor by sensing the magnetic pole pairs during said rotation,

wherein the carrier is press fit onto the second race such that the tone wheel is at a fixed depth from an outer edge of the first race, the tone wheel having a relative flatness of 0.1 mm, and a distance between the sensor and the tone wheel is fixed at approximately 1.87 mm+/−

0.27 mm.

15. The rotation sensor assembly of claim 14, further comprising a flinger press fit onto one of the first race and the second race, the flinger positioned between the tone wheel and the sensor and sealing the carrier and the tone wheel within the bearing.

16. The rotation sensor assembly of claim 15, wherein a portion of the flinger directly adjacent both the tone wheel and the sensor is straight, and the flinger is constructed of a material having a relatively low permeability.

17. The rotation sensor assembly of claim 14, wherein the first race is a stationary inner race and the second race is a rotating outer race, and wherein the tone wheel rotates with the second race and the sensor is stationary.

18. The rotation sensor assembly of claim 14, wherein the sensor is a magnetoresistive sensor.

19. The rotation sensor assembly of claim 14, wherein the sensor is configured to provide a square-wave current output indicative of a rotational speed of the second race.

20. The rotation sensor assembly of claim 14, wherein a distance between the tone wheel and the sensor is controlled by the spacer and the first race, the spacer and first race being machined parts capable of achieving extremely tight tolerances enabling a distance between the sensor and the tone wheel to be highly accurate when the spacer is abutted against the first race.

21. The rotation sensor assembly of claim 14, further comprising a controller connected to the sensor and receiving output from the sensor, wherein the controller is configured to use the output of the sensor to perform at least one of (1) determining a rotational speed of the bearing and (2) detecting a presence or absence of rotation of the bearing.