Patent ID: 6157187
Filing Date: 2000-12-05
Classification: B60T,G01D,G01P

Abstract:
An inductive wheel-speed sensor for measuring a rotational speed of a motor vehicle wheel mounted on a hub which is rotatably mounted on an axle journal, comprising:a transmitter wheel rigidly mounted on a hub remote from a wheel mounted on the hub, said transmitter wheel being formed with a multiplicity of regions of magnetizable material separated from one another by regions of substantially non-magnetizable material, and rotating with the motor vehicle wheel;at least two non-rotatably mounted magnets disposed in immediate vicinity of said transmitter wheel and separated therefrom by a predefined spacing distance such that a magnetic flux of said magnets is varied by said transmitter wheel as the transmitter wheel rotates with the motor vehicle wheel;at least two coils mounted in immediate vicinity of said magnets so that a change in the magnetic flux through said magnets is registered by said coils, said coils outputting an output signal;said magnets extending substantially parallel to a rotational axis of the wheel and having mutually opposite polarity, andsaid magnets being spaced apart such that a first of said magnets aligns with one of said regions of magnetizable material when a second one of said magnets aligns with one of said regions of substantially non-magnetizable material.