Automotive wheel speed sensor including ferromagnetic flux carrying cup closing an opening in the wheel bearing housing
AssigneeEmhart Industries, Inc.
InventorJames W. Richmond
Life of this patent
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Abstract
There is described a speed sensor that is particularly adapted to moving vehicles such as automobiles. A permanent magnet, stator assembly, and field coil are held within a cup that is adapted to mate a bearing assembly of a non-driven wheel of the vehicle. A magnetic flux is provided by the permanent magnet and when rotor poles carried by the bearing assembly rotate in close proximity to the stator assembly, the magnetic flux in turn generates an alternating voltage current in the field coil. The alternating current so generated is then fed through an electrical terminal to a vehicle computer.
Claims20
A speed sensor assembly for providing an electrical signal representative of the speed of the wheel of a vehicle, said speed sensor assembly being of the type utilizable in combination with a vehicle wheel assembly including a wheel bearing spindle rotatable on a bearing within a wheel bearing housing, said housing having an opening therein providing access to said bearing, said wheel assembly also including a cup for closing said opening, said speed sensor comprising:
- a rotor pole mechanically coupled to said vehicle wheel bearing spindle;
- a stator pole mechanically coupled to said wheel bearing housing by said cup;
- magnetic means for generating magnetic flux through said rotor pole and said stator pole;
- said magnetic means including ferromagnetic means for providing a flux path from said stator pole to said rotor pole, said ferromagnetic means comprising said cup;
- and
- means for interacting with said magnetic flux to generate said electrical signal in response to changes in said flux caused by said rotor moving with respect to said stator when said wheel moves with respect to said wheel bearing housing.
In a speed sensor assembly for providing an electrical signal representative of the speed of a vehicle wheel, said speed sensor assembly being of the type utilizable in combination with a vehicle wheel bearing assembly having a bearing enclosed in a wheel bearing housing, the housing having an opening providing access to said bearing which opening is closed by a cup, said speed sensor assembly further being of the type comprising electromagnetic means for providing said electrical signal which means includes magnetic means for generating a magnetic flux and a ferromagnetic means for carrying said magnetic flux, the improvement wherein said ferromagnetic means comprises said wheel bearing cup.
The combination of a vehicle wheel speed sensor with a vehicle wheel assembly said combination comprising:
- a wheel bearing and a wheel bearing housing supporting said wheel bearing, said housing having an opening therein providing access to said bearing;
- a wheel bearing spindle rotatable in said wheel bearing housing;
- a rotor pole fixed to said spindle;
- a stator pole;
- magnetic means for generating magnetic flux through said rotor pole and said stator pole;
- said magnetic means including ferromagnetic means for providing a flux path from said stator pole to said rotor pole said ferromagnetic means comprising a cup and said cup closing said opening and supporting said stator pole;
- and
- means for interacting with said magnetic flux to generate said electrical signal in response to changes in said flux caused by said rotor pole moving with respect to said stator pole when said spindle rotates in said housing.
Dependencies are inferred from the claim text.