Fiber optic sensor system for detecting movement or position of a rotating wheel bearing

Patent · Wed Jan 01 00:00:00 EST 1997

OSTI ID:870830

Veeser, Lynn R ^[1]; Rodriguez, Patrick J ^[2]; Forman, Peter R ^[1]; Monahan, Russell E ^[3]; Adler, Jonathan M ^[4]

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1. Los Alamos, NM
2. Santa Fe, NM
3. Ann Arbor, MI
4. Ypsilanti, MI

An improved fiber optic sensor system and integrated sensor bearing assembly for detecting movement or position of a rotating wheel bearing having a multi-pole tone ring which produces an alternating magnetic field indicative of movement and position of the rotating member. A magneto-optical material, such as a bismuth garnet iron (B.I.G.) crystal, having discrete magnetic domains is positioned in the vicinity of the tone ring so that the domains align themselves to the magnetic field generated by the tone ring. A single fiber optic cable, preferably single mode fiber, carries light generated by a source of light to the B.I.G. crystal. The light passes through the B.I.G. crystal and is refracted at domain boundaries in the crystal. The intensity of the refracted light is indicative of the amount of alignment of the domains and therefore the strength of the magnetic field. The refracted light is carried by the fiber optic cable to an optic receiver where the intensity is measured and an electrical signal is generated and sent to a controller indicating the frequency of the changes in light intensity and therefore the rotational speed of the rotating wheel bearing.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Assignee: NTN Technical Center (USA) (Ann Arbor, MI)
• Patent Number(s): US 5602946
• OSTI ID: 870830
• Country of Publication: United States
• Language: English

Related Subjects

fiber
optic
sensor
detecting
movement
position
rotating
wheel
bearing
improved
integrated
assembly
multi-pole
tone
produces
alternating
magnetic
field
indicative
magneto-optical
material
bismuth
garnet
iron
crystal
discrete
domains
positioned
vicinity
align
generated
single
cable
preferably
mode
carries
light
source
passes
refracted
domain
boundaries
intensity
amount
alignment
strength
carried
receiver
measured
electrical
signal
controller
indicating
frequency
changes
rotational
speed
bearing assembly
mode fiber
light passes
rotational speed
electrical signal
fiber optic
magnetic field
single mode
light intensity
alternating magnetic
optic cable
light generated
field generated
optic sensor
rotating wheel
single fiber
wheel bearing
improved fiber
detecting movement
domain boundaries
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