LINEAR POSITION SENSOR ASSEMBLY HAVING MAGNETIC SHIELD
First Claim
1. A linear position sensor assembly for a motor vehicle transmission comprising, in combination,a bi-directionally translating transmission component,a permanent magnet affixed to said transmission component,a permanent magnet linear contactless displacement sensor disposed in sensing relationship with said permanent magnet, said permanent magnet linear contactless displacement sensor comprising a pair of spaced apart magnetic field sensors and a high magnetic permeability metal member disposed between said pair of magnetic field sensors, anda high magnetic permeability metal shield surrounding said permanent magnet linear contactless displacement sensor on at least three sides,whereby said metal shield reduces magnetic interference from nearby transmission components induced in said permanent magnet linear contactless displacement sensor.
3 Assignments
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Accused Products
Abstract
A linear position sensor assembly having a magnetic shield minimizes interference (noise) from adjacent electrical and electromagnetic devices, particularly solenoids. The sensor assembly includes a permanent magnet linear contactless displacement (PLCD) sensor comprising a pair of magnetic field sensors which are spaced apart by a member of high magnetic permeability such as a metal bar. The sensors and metal bar are enclosed, i.e., surrounded on three sides, by a cover or shield of high magnetic permeability material such as steel or mu metal, for example. A permanent magnet is disposed in sensed proximity to the sensors and translates with a clutch actuator component. When the clutch actuator component translates axially, the two field sensors provide a signal to associated electronics having high linearity, low noise and no deadband.
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Citations
17 Claims
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1. A linear position sensor assembly for a motor vehicle transmission comprising, in combination,
a bi-directionally translating transmission component, a permanent magnet affixed to said transmission component, a permanent magnet linear contactless displacement sensor disposed in sensing relationship with said permanent magnet, said permanent magnet linear contactless displacement sensor comprising a pair of spaced apart magnetic field sensors and a high magnetic permeability metal member disposed between said pair of magnetic field sensors, and a high magnetic permeability metal shield surrounding said permanent magnet linear contactless displacement sensor on at least three sides, whereby said metal shield reduces magnetic interference from nearby transmission components induced in said permanent magnet linear contactless displacement sensor.
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8. A magnetically shielded linear position sensor assembly comprising, in combination,
a bi-directionally translating mechanical component, a permanent magnet affixed to said mechanical component, a permanent magnet linear displacement sensor disposed in sensing relationship with said translating permanent magnet, said permanent magnet linear displacement sensor comprising a pair of spaced apart magnetic field sensors and a high magnetic permeability member disposed between said pair of magnetic field sensors, and a high magnetic permeability shield partially surrounding said permanent magnet linear displacement sensor, whereby magnetic interference from nearby components is reduced by said metal shield.
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15. A linear position sensor assembly for a motor vehicle component comprising, in combination,
a bi-directionally translating element of such component, a permanent magnet secured to said element for bi-directional translation therewith, a permanent magnet linear displacement sensor disposed in sensing relationship with said permanent magnet, said permanent magnet linear displacement sensor comprising a pair of spaced apart magnetic field sensors and a high magnetic permeability member disposed between said pair of magnetic field sensors, and a high magnetic permeability shield surrounding said permanent magnet displacement sensor on three sides, whereby said shield reduces magnetic interference from nearby magnetic and electromagnetic elements of such motor vehicle component.
Specification